What is a workplace investigation, and when is one needed?

A workplace investigation is an impartial, structured fact-finding process an employer uses to determine what happened when there are contested allegations of policy, ethics, or legal violations — most commonly harassment, violence, discrimination, or serious misconduct (theft, fraud) — and in Ontario the trigger can be a formal complaint, an informal verbal report, or the employer simply becoming aware of a possible incident.

The Association of Workplace Investigators (AWI), the leading professional body for the field with a Canadian chapter, defines the purpose plainly: an impartial investigation is conducted “so that an employer can determine what occurred when there are contested allegations affecting the workplace that involve a potential violation of the employer’s policies, procedures, standards, ethics, or the law,” and its point “is to provide a fair and impartial process for the complainant and respondent and to reach reasoned findings based on the information gathered.” In practice it is a structured sequence: receive/triage the allegation, plan scope and investigator, interview the complainant, respondent, and witnesses, gather documentary evidence, weigh credibility, reach findings on a balance of probabilities, and report.

The typical triggers are allegations of workplace harassment (including sexual harassment), workplace violence or threats, discrimination on a protected ground, and other serious misconduct such as theft or fraud. In Ontario specifically, the trigger threshold is low and does not require a formal complaint: an employer’s duty can be engaged by a verbal report, a direct observation by a manager, or anonymous/third-party information — the employer is expected to act once it becomes aware of a possible incident. An employer may also choose to investigate even where not legally required — for example, before terminating for just cause — because doing so produces evidence-based, defensible decisions.

The Ontario/SMB lens: small employers often lack an obvious neutral internal investigator (the HR person may report to the respondent), which is what drives many KW firms toward an external investigator (see sibling note). This note does not restate the statutory duty to investigate — the OHSA “appropriate in the circumstances” obligation, Human Rights Code duties, and the governing case law (e.g., Metrolinx v. Amalgamated Transit Union, Local 1587) belong to the compliance pipeline.

Pillar anchor: Workplace investigations. Links down to COMPLIANCE for the legal duty to investigate and statutory triggers.

Related notes

What makes a workplace investigation defensible and procedurally fair? — A defensible workplace investigation is one that satisfies procedural fairness (natural justice): an impartial, unbiased investigator; notice to the respondent of the allegations against them; a genuine opportunity for both sides to be heard and respond; a thorough, timely, well-documented process; and an appropriately scoped inquiry — with an external investigator preferred where impartiality, seniority of the respondent, complexity, or litigation risk are in play.