How to conduct a workplace investigation
Workplace investigations are serious processes that can have significant legal and business consequences. Done properly, they resolve issues fairly and protect both employees and the business. Done poorly, they expose you to unfair dismissal claims, discrimination allegations, and reputational damage.
Written by
Steve Harris
General information only – not legal advice
Workplace investigations involve employment law, anti-discrimination law, workplace health and safety obligations, and potential litigation. This guide provides general information about conducting workplace investigations for Australian businesses. Serious allegations such as harassment, discrimination, or misconduct that may lead to termination should be handled with extreme care. We strongly recommend seeking independent legal advice before commencing an investigation, particularly for complex or high-risk matters. It does not constitute legal, HR, or professional advice and should not be relied on as a substitute for advice specific to your business, workforce, or circumstances.
What is a workplace investigation?
A workplace investigation is a formal, structured process to examine complaints or allegations of misconduct, policy breaches, or workplace issues. Investigations are triggered by complaints of bullying, harassment, discrimination, theft, fraud, safety breaches, or serious breaches of workplace policies.
According to the Fair Work Ombudsman, workplace investigations must be fair, objective, and thorough. Fair Work Inspectors conduct investigations into alleged contraventions of workplace laws, collecting evidence such as time and wages records, employment contracts, and interviewing employees.
Legal implications
Workplace investigations have significant legal consequences
Employers who fail to comply with investigation requirements can face significant penalties. Penalty amounts are indexed and updated regularly – verify current figures with the Fair Work Ombudsman. Mishandling can expose your business to unfair dismissal or discrimination claims.
Before you proceed - mandatory checklist
Before conducting a workplace investigation, confirm you have addressed each of these items:
For serious allegations, stop and seek professional advice before proceeding. Mishandled investigations can result in claims being invalidated.
Sample investigation plan
Here's what a typical workplace investigation plan looks like with the key sections highlighted.
A typical investigation plan includes:
- Complaint details — Who, what, when, where
- Scope — What's being investigated and why
- Evidence plan — Who to interview, what to collect
- Timeline — Expected completion date
- Confidentiality — How information will be protected
Key principles of workplace investigations
Every investigation must follow these principles to ensure fairness, objectivity, and defensibility.
Fairness and objectivity
The investigator must be impartial and objective. You're not trying to prove guilt—you're trying to establish facts. Both parties must be given a fair opportunity to present their side.
Confidentiality
Maintain confidentiality as much as possible to protect the privacy and dignity of all parties. Only share information with those who genuinely need to know.
Thoroughness
Investigate all relevant information comprehensively. Interview all parties and witnesses, collect all relevant documents, and follow up on all leads.
Documentation
Keep detailed, contemporaneous records of the entire investigation process. Document every interview, piece of evidence, and step taken.
Procedural fairness is not optional
Procedural fairness (also called natural justice) is a fundamental legal requirement established in case law such as Foley v Melbourne Health [2015] FWC 4821. The respondent must be told what they're alleged to have done, provided with relevant evidence, given a reasonable opportunity to respond, and have their response considered before a decision is made. Failing to provide procedural fairness can invalidate the entire investigation and expose you to unfair dismissal claims.
Selecting the right investigator
One of the most critical decisions in a workplace investigation is choosing who will conduct it. The investigator must be impartial, qualified, and appropriate for the complexity and seriousness of the allegations.
Internal investigator
Suitable for less complex matters where impartiality can be maintained. Usually an HR manager or senior manager with no connection to the parties.
External investigator
Essential for serious allegations (harassment, discrimination, potential termination). Provides independence, expertise, and legal defensibility.
When to use an external investigator
Workplace investigation checklist
Use this checklist to ensure you complete all critical steps in the investigation process.
Complaint documented
EssentialRecord details, dates, people involved
Investigator appointed
EssentialChoose impartial, qualified person
Investigation plan created
EssentialScope, objectives, timelines defined
Interim measures considered
Decide on temporary actions if needed
Complainant interviewed
EssentialFull account of allegations documented
Respondent notified and interviewed
EssentialGiven chance to respond to allegations
Witnesses interviewed
Open-ended, neutral questions asked
Documents collected
Emails, chats, CCTV, rosters, etc.
Evidence analysed
EssentialCredibility, consistency evaluated
Investigation report written
EssentialFindings and recommendations documented
Three ways to manage workplace investigations
Each method has trade-offs. Here's how they compare.
Manual process
Paper forms, handwritten notes, and email. Works but is time-consuming and high-risk if documentation is poor.
Best for: Very small businesses with rare investigations
Pre-made forms and checklists. More structured but still requires manual tracking and storage.
Best for: Small businesses getting started
Centralised documentation, secure storage, audit trails, and compliance tracking. Professional and defensible.
Best for: Any business that values risk management
How to conduct a workplace investigation
Follow these 5 steps to conduct fair, thorough, and defensible workplace investigations.
Receive and assess the complaint
When a complaint is raised, the first step is to document everything and determine the seriousness and scope of the allegation.
Key actions:
- Document everything: Get detailed accounts, dates, times, people involved, and save relevant communications
- Confirm scope: Determine if it's a formal complaint (e.g., bullying, harassment) and if immediate action is needed
- Assess urgency: Decide if the matter requires immediate intervention or interim measures
- Review relevant policies: Check your workplace policies on complaints, conduct, and investigation procedures
Plan the investigation
A structured investigation plan ensures procedural fairness and that all relevant evidence is collected.
Key actions:
- Choose investigator: Select someone impartial, objective, and knowledgeable (internal HR or external consultant)
- Define scope and objectives: Clearly outline what's being investigated and its boundaries
- Create a plan: List individuals to interview, evidence to collect, timelines, and confidentiality protocols
- Consider interim measures: Decide if temporary measures (like suspension with pay or roster changes) are needed
Gather evidence and interview parties
Interviews are legally sensitive. What you say, how you ask questions, and what you promise can affect the validity of your investigation. For serious matters, seek legal guidance on interview protocols.
Collect all relevant information through interviews and documentation while ensuring fairness to all parties.
Key actions:
- Interview complainant first: Get full details, clarify allegations, and understand the impact
- Interview respondent: Give them clear summary of allegations and chance to respond fairly
- Interview witnesses: Ask open-ended, neutral questions without leading or suggesting answers
- Collect documents: Get emails, chats, policies, CCTV footage, rosters, timesheets, or other relevant records
Analyze evidence and make findings
Findings may lead to disciplinary action or termination. Errors in this step can invalidate the entire investigation and expose your business to legal claims. Ensure procedural fairness is maintained throughout.
Evaluate all the information objectively, weigh the credibility of evidence, and reach a conclusion.
Key actions:
- Evaluate evidence: Weigh credibility and consistency, applying "balance of probabilities" (more likely than not)
- Stay objective: Focus on facts, not assumptions, personal opinions, or hearsay
- Ensure procedural fairness: Allow parties to review and correct statements before finalizing
- Determine findings: Decide if allegations are substantiated, partially substantiated, or not substantiated based on evidence
Report and take action
Document your findings in a formal report, communicate the outcome, and implement any necessary actions.
Key actions:
- Write report: Summarize allegations, evidence collected, analysis, and findings clearly
- Communicate outcome: Inform relevant parties of the findings (complainant, respondent, management)
- Take action: Implement disciplinary measures, procedural changes, or training as needed
- Follow up: Monitor the situation to ensure the issue is resolved and no retaliation occurs
Investigation interview techniques
Interviews are the most critical evidence-gathering tool in workplace investigations. How you conduct them can determine the quality and reliability of your findings. Use these evidence-based techniques to conduct fair, thorough interviews.
Start broad, then narrow
Begin with open-ended, non-threatening questions before moving to specifics. This puts interviewees at ease and gets more complete information.
Example progression:
- "Tell me about your typical work day"
- "What happened on Tuesday morning?"
- "What exactly did Sarah say at that moment?"
Reverse-order questioning
Ask interviewees to recount events in reverse chronological order. Research shows this is easy if the account is truthful, but harder if it's memorized or fabricated.
How it works:
- Get the full account chronologically first
- Then ask them to retell it backwards
- Note any inconsistencies or difficulties
Use open-ended questions
Avoid yes/no questions or leading questions. Open-ended questions reveal more detail and reduce the risk of influencing responses.
❌ Poor questions:
"Did John yell at you?" (yes/no)
"John yelled at you, didn't he?" (leading)
✓ Better questions:
"Describe what John said and did."
"How did John communicate with you?"
Document meticulously
Take detailed, contemporaneous notes during interviews. Record exact quotes where possible. Use digital HR records to maintain secure, timestamped interview documentation.
Best practices:
- Record date, time, location, attendees
- Use direct quotes for key statements
- Let interviewee review and correct notes
- Store securely with audit trail
Interview sequence and support persons
The order you conduct interviews matters. Best practice sequence: complainant first (to clarify allegations), witnesses next (uncontaminated accounts), respondent last (can respond to all evidence), then complainant again if needed (to address new information).
Support persons and confidentiality
Parties may request a support person (not a legal representative unless serious misconduct is alleged). Emphasize confidentiality obligations to all participants, but never guarantee absolute confidentiality—you may need to disclose information to substantiate findings or meet procedural fairness requirements.
Investigation tips
Follow these principles for investigations that are fair, defensible, and legally compliant.
Be impartial
The investigator must be neutral and objective, with no stake in the outcome.
Maintain confidentiality
Only share information with those who need to know. Protect privacy as much as possible.
Ensure fairness
Give both parties a fair chance to tell their side and respond to allegations.
Stay objective
Base findings on evidence, not assumptions, personal opinions, or hearsay.
Document thoroughly
Keep detailed records of every step, interview, and piece of evidence collected.
Act on findings
Implement recommendations and take appropriate disciplinary or corrective action.
Fair work ombudsman investigation powers
The Fair Work Ombudsman has significant investigation powers. Understanding these can help you conduct your own investigations to a similar standard:
Learn more about Fair Work investigation processes at Fair Work Ombudsman.
Manage investigations with RosterElf HR hub
Conduct investigations with confidence using secure, centralised HR documentation and audit trails.
Centralised documentation
Store all investigation records, interview notes, and evidence in one secure location with complete audit trails.
Role-based access control
Maintain confidentiality with granular permissions ensuring only authorized personnel can access sensitive investigation records.
Complete audit trails
Every action is logged and timestamped, providing defensible records if your investigation is challenged.
Integrated with employee records
Link investigation outcomes directly to employee files for complete compliance documentation.
No credit card required
Feature comparison
See exactly how each investigation method stacks up across key features.
Investigation planning
Evidence tracking
Interview records
Document storage
Timeline tracking
Report generation
Audit trail
Confidentiality
| Feature | Manual | Templates | HR software |
|---|---|---|---|
| Investigation planning | 2-4 hours | 1-2 hours | 30-60 minutes |
| Evidence tracking | Manual notes | Spreadsheet | Centralised system |
| Interview records | Paper/Word | Template docs | Digital forms |
| Document storage | Filing cabinet | Shared drive | Secure cloud storage |
| Timeline tracking | Manual calendar | Spreadsheet | Automated tracking |
| Report generation | Fully manual | Semi-manual | Template-based |
| Audit trail | Difficult | Basic | Complete audit log |
| Confidentiality | Reliant on process | Better controls | Role-based access |
Common investigation mistakes
Learn from others' errors. These mistakes can invalidate investigations and expose businesses to legal claims.
Failing to act promptly
Consequence: Delays can worsen the situation, allow evidence to be lost, and damage trust in the process
Solution: Begin the investigation as soon as reasonably practicable after receiving the complaint. Use digital HR records to track timelines
Lack of impartiality or perceived bias
Consequence: Investigation findings will be challenged, and parties will lose confidence in the process
Solution: Choose an investigator with no connection to the parties involved. Consider external investigators for serious matters. Document grievance procedures clearly in your workplace policies
Poor documentation practices
Consequence: Inadequate records make it impossible to defend findings or comply with legal requirements
Solution: Document every step, interview, and piece of evidence collected. Store records securely using centralised HR systems
Denying procedural fairness to respondent
Consequence: Findings can be challenged in court, exposing the business to unfair dismissal or adverse action claims
Solution: Always give the respondent a fair opportunity to hear and respond to allegations. Follow your complaints policy and ensure natural justice
Inadequate follow-up after investigation
Consequence: The issue may recur, complainants feel unsupported, and workplace culture deteriorates
Solution: Implement recommendations, monitor for retaliation, and check in with parties. Document outcomes in HR records
Post-investigation aftercare and monitoring
The investigation doesn't end with the report. Post-investigation aftercare is critical for rebuilding trust, preventing retaliation, and ensuring the workplace returns to normal operations. Research shows that poorly managed aftercare can negate the benefits of even well-conducted investigations.
Communication and closure
Inform relevant parties of the outcome without breaching confidentiality. Explain what actions will be taken (if any) and that the matter is now closed.
- Provide outcome to complainant and respondent
- Clarify what disciplinary action was taken (if appropriate)
- Explain confidentiality expectations going forward
Monitor for retaliation
Actively monitor the workplace for any signs of retaliation against the complainant or witnesses. Retaliation is a serious workplace law breach and can expose your business to significant liability.
- Check in with complainant regularly (weekly for first month)
- Watch for roster changes, exclusion, or hostility
- Document all follow-up actions in HR records
Implement recommendations
Act on investigation findings promptly. This may include policy updates, training, system changes, or disciplinary action. Document implementation to demonstrate organizational commitment.
- Update workplace policies if gaps identified
- Deliver training on respectful workplace behavior
- Review and improve complaint-handling procedures
When findings are not substantiated
If allegations are not substantiated, this does NOT mean the complainant was lying or made a vexatious complaint. It simply means there was insufficient evidence to prove the allegations on the balance of probabilities.
Reputation management for respondents
When allegations are not substantiated, respondents may feel their reputation has been damaged. Consider: offering an apology for the stress of the process (not for the investigation itself), reaffirming their value to the organization, and ensuring they're not treated differently going forward. Balance this with supporting the complainant's right to raise concerns without retaliation.
Ongoing workplace culture monitoring
Use the investigation as an opportunity to strengthen workplace culture. Consider conducting anonymous pulse surveys, reviewing complaint trends, and ensuring managers understand their role in preventing future issues.
Download free investigation templates
Get started with our library of free HR templates. Written by HR experts, ready to customise.
Frequently asked questions about workplace investigations
- A workplace investigation is typically triggered by a formal complaint alleging serious misconduct such as bullying, harassment, discrimination, theft, fraud, safety breaches, or violations of workplace policies. Investigations may also be initiated by management if they become aware of concerning behaviour.
- The investigator should be impartial, objective, and have no connection to the parties involved. For minor matters, an internal HR manager may be appropriate. For serious allegations (harassment, discrimination, or matters that may lead to termination), an external investigator with relevant qualifications and experience is recommended.
- Procedural fairness (also called natural justice) means giving the respondent a fair chance to hear the allegations against them and respond before any decision is made. It includes: telling the person what they're alleged to have done, providing relevant evidence, giving them a reasonable opportunity to respond, and considering their response before reaching a conclusion.
- Workplace investigations use the 'balance of probabilities' standard, meaning the finding should reflect what is more likely than not to have occurred based on the available evidence. This is a lower standard than the criminal standard of 'beyond reasonable doubt'. You assess the credibility, consistency, and reliability of evidence from all parties.
- The timeframe depends on the complexity of the allegations, number of witnesses, and availability of parties. Simple matters may be resolved in 2-4 weeks. Complex investigations involving multiple witnesses and extensive documentation may take 6-12 weeks. Investigations should be completed as promptly as possible while ensuring thoroughness and fairness.
Regulatory sources
This guide is aligned with official Australian workplace regulations on handling disputes and complaints.
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