When a serious complaint lands on an employer’s desk, one of the first decisions is also one of the most consequential: Who investigates? Hand it to HR, or retain an outside investigator? Get that choice right and the process holds up. Get it wrong and even a well-run investigation can be set aside, sometimes at your expense.
Key Takeaways
- Ontario’s Occupational Health and Safety Act requires an investigation “appropriate in the circumstances”, it allows either an internal or an external investigator, as long as that person is impartial, not under the alleged harasser’s control, and competent to do the work.
- Internal HR can handle lower-risk, less complex matters where a trained investigator has no conflict of interest and the capacity to do it properly.
- An external investigator is the safer choice when the respondent is a senior leader or owner, when the allegations are serious (sexual harassment, violence, discrimination), or when the matter is likely to be litigated or scrutinized.
- Check your own workplace harassment program first, it may already dictate who investigates, or require an external investigator in defined situations.
- Getting it wrong is costly: a biased or inadequate internal investigation can be given little weight, expose the employer to damages, and a Ministry inspector can order an external investigation at the employer’s expense.
Start With the Law, and Your Own Policy
Ontario’s Occupational Health and Safety Act (OHSA) does not tell employers to use an internal or an external investigator. It requires something more flexible: an investigation that is “appropriate in the circumstances.” The person who conducts it, internal or external, must be impartial, must not be involved in the incident or under the alleged harasser’s direct control, and must have the knowledge to do the job properly. That standard is the lens for the entire internal-versus-external question.
Before weighing anything else, read your own workplace harassment program. Many programs already name who receives and investigates complaints, and a well-drafted one requires an external investigator in defined situations, most commonly when the person complained about is an owner, senior executive, or member of senior management. If your policy speaks, follow it; departing from your own procedure is itself a source of risk.
When Internal HR Can Handle It
For a great many complaints, an internal investigation is entirely appropriate, and often faster, less expensive, and less disruptive than bringing in an outsider. Internal HR is usually a sound choice when the matter is relatively contained: a lower-stakes interpersonal conflict or a straightforward policy breach, where the facts are narrow and the risk of litigation is low.
Three conditions have to hold. The investigator needs genuine independence from everyone involved, no reporting line to the complainant or respondent, and no personal stake in the outcome. They need to be trained, familiar with procedural fairness, interviewing, credibility assessment, and the mechanics of conducting a workplace harassment investigation, not improvising. And they need the time and capacity to do it properly, which is no small thing when a thorough investigation can run weeks alongside a full-time job. Where all three hold, keeping it in-house is often the right call, and worth investing in through proper HR advisory and training.
When to Bring in an External Investigator
The calculus flips as the stakes rise. An external investigator is usually the wiser choice in several recurring situations.
The first is seniority. When the respondent is an owner, an executive, or the head of HR itself, no internal investigator can credibly claim independence, and Ontario’s own guidance flags exactly this scenario as one calling for an external investigator. The second is severity: allegations of sexual harassment, workplace violence, discrimination, or possible criminal conduct carry legal and reputational stakes that reward independence and specialized experience. The third is defensibility, where a matter is likely to end up before the Human Rights Tribunal of Ontario, a court, or a regulator, the neutrality and expertise of an outside investigator make the findings far harder to attack. Complexity is the fourth: many witnesses, a long history, or difficult credibility questions can overwhelm an internal team. And in a small organization where everyone knows everyone, an outsider may simply be the only genuinely impartial option.
Perception matters as much as reality here. An internal investigation can be scrupulously fair and still fail if the parties, or, later, an adjudicator, reasonably doubt the investigator’s independence. On a serious or senior-level file, that appearance risk alone often justifies going external.
The Cost of Getting the Choice Wrong
Choosing the cheaper, faster internal option on a matter that needed an outsider is a false economy. An investigation seen as biased or inadequate tends to be given little weight when it is later scrutinized, can support an adverse inference against the employer, and can feed claims for aggravated or moral damages and constructive dismissal.
There is also a distinctly Ontario consequence. Under the OHSA, a Ministry inspector who is not satisfied with an employer’s investigation can order one to be conducted by an impartial person with specified qualifications, at the employer’s expense. In other words, a botched internal investigation can end with the employer paying for the external investigation it tried to avoid, on top of the damage already done. Deciding well at the outset is far cheaper than being ordered to start over.
You Don’t Have to Choose in the Dark
The internal-versus-external decision is really made at the threshold, before anyone is interviewed, and it benefits from advice. A threshold assessment helps an employer size up the complaint, its risk, and the right process before committing to a path. It is also why many employers involve legal counsel early: counsel can help decide whether the matter can stay in-house, oversee an internal investigator, retain a suitable independent investigator, and structure the surrounding work so that legal advice remains privileged, something an HR-only process cannot offer.
The choice is not simply internal or external. The real question is whether the investigation will be impartial, competent, and defensible, and which route gets you there for this particular complaint. When in doubt on a serious or senior-level matter, the safer, and usually cheaper, answer is to bring in an independent workplace investigation professional.
Facing a Complaint and Unsure Who Should Investigate?
Greenwood Law helps Ontario employers make the call, assessing the risk, conducting independent workplace investigations, overseeing internal ones, and defending the outcome if it is later challenged. Contact Greenwood Law for a confidential consultation before you assign the file.
