An investigation should test evidence, not prove a pre-decided outcome. Clear allegations, an impartial investigator and a transparent report make the eventual decision more defensible.
What is a workplace investigation?
A workplace investigation is a structured fact-finding process used to examine an allegation, complaint or disputed event. It may form part of a grievance, disciplinary, whistleblowing, safeguarding or other internal procedure.
The investigator does not normally decide the disciplinary outcome. Their role is to gather relevant evidence, test competing accounts and present findings so an authorised decision-maker can act fairly.
- Bullying, harassment or discrimination allegations
- Suspected misconduct, fraud or policy breaches
- Health and safety or safeguarding concerns
- Complex grievances or whistleblowing reports
Set a clear scope before evidence is gathered
Terms of reference keep the work focused. They should identify the allegations or questions to be examined, the investigator's authority, the expected report format and any important boundaries.
Scope may need to change if credible new information appears. Record why the change is necessary and communicate it to the relevant parties so nobody is surprised by the process.
- Separate each allegation into a testable question
- Identify relevant policies and potential evidence sources
- Consider conflicts of interest and independence
- Set realistic milestones without promising a fixed outcome date
Plan interviews and documentary evidence
Evidence can include emails, messages, meeting notes, system records, policies, CCTV, documents and witness accounts. Collect proportionately and preserve original material where possible.
Interview questions should be open and neutral. Give each person a fair opportunity to explain their account, identify supporting evidence and respond to material points that conflict with it. Confidentiality should be explained carefully: information is restricted to those who need it, but absolute secrecy cannot usually be promised.
- Begin with background and chronology before testing detail
- Distinguish direct recollection from assumption or hearsay
- Confirm notes or statements using a consistent process
- Follow up gaps and contradictions rather than ignoring them
Reach evidence-based findings
The report should explain the allegation, evidence considered, relevant factual disputes and the reasoning behind each finding. Workplace investigations usually apply the civil standard—the balance of probabilities—unless a policy lawfully specifies otherwise.
A balanced report records evidence that supports and undermines an allegation. It should avoid emotive language, speculation and recommendations outside the investigator's remit.
- Use a clear finding for every allegation
- Explain the weight given to important evidence
- Record limitations or unavailable evidence
- Keep appendices and an orderly evidence index
When should an investigation be independent?
External independence can be valuable when allegations involve senior leaders, internal relationships create a conflict, the issues are especially sensitive or the organisation lacks time and specialist experience.
A competent external investigator brings structure and neutrality, but the employer should still appoint an appropriate decision-maker and retain responsibility for the wider employment process.
- Serious or high-profile allegations
- Multiple parties or extensive evidence
- Low confidence in an internal process
- A need for specialist interviewing and report-writing
Originally published 7 January 2025. This guide provides general information for employers and is not legal advice. Employment law and guidance can change; check current requirements and take advice on the facts of a live situation.