Ontario's Special Investigations Unit is investigating two separate deaths on Saturday night that followed interactions with Toronto police officers.
The first happened at a home on Castledene Crescent in Scarborough at about 7:30 p.m.
According to the provincial police watchdog, police were called to the residence for an "unknown trouble call."
The SIU release is sparse on details, saying only that a police negotiator was involved and spoke with a man who "sustained a serious injury" over the course of the negotiation.
The man received first aid from officers, then from paramedics. The 41-year-old man died in hospital, according to the SIU. A post-mortem is scheduled for Monday.
A few hours after the Scarborough incident, police responded to a call for a man in distress at a home on Church Street near the city's core.
In a separate news release, the SIU said police found a man barricaded inside at about 11:30 p.m.
Once officers got into the residence, the SIU release said, police "located the man in medical distress."
Paramedics were called but the 34-year-old died, the SIU said.
Anyone with information that might be relevant to either case, including video evidence, is being urged by the SIU to contact investigators at 1-800-787-8529.