Quebec's independent police watchdog is investigating the death of a 77-year-old man who was doused with pepper spray after police responded to a call about a domestic disturbance.

The incident took place at around 6 p.m. Saturday in Sainte-Hélène-de-Bagot, Que., located about 70 kilometres east of Montreal.

The independent investigations bureau (BEI) issued a statement later that evening, providing scant details of the event.

Provincial police responded to a call about a domestic situation involving a couple and, once on the scene, police decided to arrest the man, the statement says.

Police deployed their pepper spray, handcuffed the man and then saw that he was having breathing problems.

An ambulance was called in and the man died in hospital at around 7:50 p.m.

The first step is to determine whether the initial information is accurate, the BEI says.

Just before 5 a.m. Sunday, the agency tweeted that it is on the scene of the incident, conducting its investigation.

The BEI is responsible for investigating all cases where a person other than a police officer on duty dies, suffers a serious injury or is injured by a firearm during a police intervention.

In accordance with BEI's regulations, a city of Montreal police officer will act as a supporting police force in this investigation, providing one forensic identification technician who will work under the supervision of BEI investigators.

The active ingredient in pepper spray is oleoresin capsicum (OC) — the stuff that makes hot peppers hot — and it is deployed from an aerosol can with the push of a button. It causes symptoms such as throat discomfort, eye pain and temporary blindness.

It has also been known to cause adverse reactions in people who, for example, have asthma or take certain medications.

In 2017, Correctional Service Canada studied the use of OC spray and found it to be a usually safe means of defusing a situation without lasting injury.

However, the agency also found there is "always the potential for harm when using any Use of Force (UoF) intervention option, and evidence suggests that OC spray has occurred proximate to both injuries and deaths."