When Does an Ontario Employer Need an Independent Workplace Investigator?

The Occupational Health and Safety Act requires Ontario employers to investigate workplace harassment complaints. The statute does not require that the investigation be conducted by an independent third party. But there are circumstances where conducting the investigation internally is not appropriate -- and in some situations, it is precisely what the Human Rights Tribunal of Ontario will use against you when it assesses whether the employer met its obligations.

The question is not whether you can conduct the investigation internally. The question is whether an internal investigation will be credible, independent, and procedurally sound enough to withstand the scrutiny that follows if the outcome is challenged.

When the Respondent Is a Manager, Director, or Owner

When the person accused holds authority over HR, over the person who would conduct the investigation, or over key witnesses, the independence of an internal investigation is compromised before it begins. The HRTO has found investigations inadequate where the investigator reported to the respondent or where the respondent had influence over the career of anyone involved in the process. Independence is not just an ethical requirement here -- it is an evidentiary one. A finding made by an investigator who is not independent is a finding that the Tribunal will not credit, regardless of whether that finding happens to be correct.

When HR Lacks Dedicated Investigation Capacity

Conducting a workplace investigation is not a generalist HR skill. It requires specific knowledge of procedural fairness obligations, credibility assessment methodology, the balance of probabilities standard, and report-writing to a level that can withstand subsequent scrutiny by an adjudicator who is looking for precisely the gaps that most generalist investigators leave. A small HR function asked to investigate a serious harassment allegation is being set up to produce a report that will not hold up -- and the employer will be responsible for that failure.

When There Is a Prior Relationship With Either Party

HR business partners who have counselled either the complainant or respondent on previous performance or conduct issues, who have a social relationship with either party outside of work, or who have taken a prior documented position on the dynamic between the parties cannot conduct a credible independent investigation. The appearance of conflict is treated as actual conflict. The HRTO is not interested in whether the investigator subjectively believed they were neutral -- it is interested in whether a reasonable observer would conclude they could be.

When the Complaint Involves a Protected Ground Under the OHRC

Harassment complaints that allege conduct connected to a protected ground under the Ontario Human Rights Code -- race, sex, disability, religion, sexual orientation, gender identity, family status -- carry additional legal weight beyond the OHSA investigation obligation. An inadequate investigation in these circumstances does not just expose the employer to Ministry of Labour orders. It creates direct HRTO exposure: general damages currently ranging from $15,000 to $50,000 or more per complainant, plus the possibility of public interest remedies and costs awards. The quality of the investigation determines whether the employer has a defence.

When a Previous Internal Investigation Is Being Challenged

If an employee has filed an HRTO application alleging that a prior investigation was inadequate, biased, or never conducted at all, commissioning an independent investigation at this stage has two functions. It demonstrates the employer’s commitment to a proper process. And it produces findings that the Tribunal can consider, rather than leaving the employer in the position of defending a process that has already been attacked. The fact that the independent investigation was commissioned in response to an application does not eliminate its value -- the Tribunal is interested in whether the employer ultimately took the complaint seriously.

The Default Position for Ontario SMEs

An Ontario employer with fewer than 50 employees and no dedicated HR function has almost no circumstances in which internal investigation is appropriate for a serious allegation. There is no realistic capacity to produce an investigation that meets the procedural fairness standard the HRTO applies, and the cost of getting it wrong -- a second investigation, Tribunal damages, legal costs to defend a deficient process -- consistently exceeds the cost of commissioning an independent investigation from the outset.

The right question is not whether you can investigate internally. It is whether the investigation you can conduct will hold up.

What Standard the HRTO Actually Applies

The Tribunal does not require a perfect investigation. It requires that the employer took reasonable steps to investigate in a timely manner, that the respondent was given the allegations in sufficient detail to respond meaningfully before their interview, that all material witnesses were heard, and that the findings were based on the evidence rather than pre-existing assumptions. These standards are achievable -- but they require a process that is planned, executed, and documented at every stage. Most informal internal processes fail not because the investigator was dishonest but because the process was undocumented.