No. A formal complaint does not need to be filed before an employer’s duty to investigate is triggered.
Employers may have a duty to investigate workplace harassment even where no official or formal complaint has been made. If an employer becomes aware of potentially inappropriate conduct – whether through an informal comment, a supervisor’s observation, workplace rumors, or a witness report – it may be required to investigate and address the issue.
In other words, an employer cannot necessarily avoid its obligations simply because an employee has not submitted a formal complaint. Once the employer becomes aware of allegations or conduct that could constitute workplace harassment, action should be taken and legal obligations have been triggered.
What does the law say?
In Ontario, employers have a duty under section 32.0.7 of Ontario’s Occupational Health and Safety Act (“OHSA”) to investigate any complaint or incident of workplace harassment, “that is appropriate in the circumstances”. Likewise, under Ontario’s Human Rights Code (“the Code”) an employer is required to “reasonably” investigate a complaint or incident involving any alleged discrimination or harassment based on a protected grounds under the Code.
In Metrolinx v. Amalgamated Transit Union, Local 1587, 2024 ONSC 1900, the Divisional Court confirmed that employers have a duty to investigate allegations of workplace harassment even where the individual who raises the concern declines to file a formal complaint or participate in the employer’s complaint process.
In this case, while investigating an unrelated matter, the employer learned that several employees had made negative, derogatory, and sexist comments about a female employee in a group chat. These comments made references to the female employee performing sexual favours for career advancement. The employee had received screenshots of the messages and brought them to the attention of her supervisor. However, she did not file a formal complaint at the time as she did not want the matter to be investigated.
Nonetheless, despite the absence of a formal complaint, the employer proceeded with an investigation. The Court held that the employer’s decision to do so was both reasonable and consistent with its statutory obligations under the OHSA.
The Court confirmed that an employer’s duty to investigate may arise once it becomes aware of allegations of workplace harassment, regardless of whether the affected employee chooses to engage with the formal complaint process.
There are many situations in which employees raise concerns but do not wish to formally engage in the complaint process, instead seeking only to make the employer aware of the issue. This places employers in a difficult position, as they must balance their duty to investigate and address workplace concerns with the employee’s preference not to pursue a formal process.
However, the Court emphasized that an employer’s duty to investigate exists to protect all employees, not merely those who file complaints or are directly subjected to harassment or discrimination. It held that limiting the duty in this manner would be inconsistent with an employer’s obligation to maintain a workplace free from harassment. The Court further recognized that allowing harassing or discriminatory conduct to continue unchecked can negatively impact the workplace as a whole and may adversely affect many, if not all, employees. This duty was reaffirmed by the Court of Appeal for Ontario in Metrolinx v. Amalgamated Transit Union, Local 1587, 2025 ONCA 415, at para. 36.
What if the complaint or report is anonymous?
Anonymity does not, in itself, end the inquiry. The key question is whether the employer has sufficient information to identify any potential incident(s) of workplace harassment or discrimination and take reasonable steps in response.
If the complaint contains enough detail – for example, names, dates, locations, or a description of the alleged conduct – the employer is generally expected to:
- Assess the credibility and specificity of the allegation(s).
- Determine whether the issue, if substantiated, could amount to workplace harassment or discrimination.
- Take reasonable investigative steps, which may include interviewing witnesses and reviewing relevant records.
If the available information in the anonymous complaint is too limited, the employer’s response may be confined to monitoring the situation, seeking clarification where possible, and carefully documenting why further investigative steps could not presently be taken. Anonymous complaints can be problematic, particularly if the employee is not prepared to be interviewed and the outcome will require a credibility assessment. On the other hand, many employers maintain whistleblower policies and reporting portals, and there are circumstances in which the information provided through those channels is sufficiently detailed and serious to trigger a formal investigation.
Why does this matter?
Failing to investigate known concerns, even if raised informally, can:
- Violate an employer’s legal obligations under the OHSA and the Code.
- Expose the employer to liability and penalties for breaching those obligations.
- Lead to reputational harm.
- Undermine employee trust, morale, and workplace safety.
If you need guidance navigating the workplace investigation process, the Workplace Investigations team at Soloway Wright LLP can assist.
About the Author
Mareike is an Associate in the Labour, Employment & Public Law and Workplace Investigations Groups at Soloway Wright LLP. She is frequently retained as an independent third-party investigator to conduct workplace investigations and deliver findings even in the thorniest cases. Leveraging her extensive background in human rights, she regularly provides advice to complainants, respondents and employers on how to effectively navigate and manage the investigation process.
DISCLAIMER: This article is for general information purposes only and is not (and should not be construed as) legal advice. The information contained herein summarizes only certain aspects of the subject matter and is not a comprehensive review of applicable law.
