A 56-year-old man who was taken into custody in connection with an assault investigation died in police custody Tuesday.

The Winnipeg Police Service said the man was arrested after another man in his 50s was taken to hospital in stable condition after an assault at a residence in North Point Douglas.

The suspect was found near Main Street and Sutherland Avenue and taken to the North District police station, where he was eventually found unresponsive in a holding cell, police said.

He was pronounced dead after being taken to hospital in critical condition.

The Independent Investigation Unit of Manitoba is investigating and said police reported that the man was arrested around 7:15 p.m. in connection with two assault allegations and found unresponsive three hours later, at 10:15 p.m.

The IIU also said a request has been made to the Manitoba Police Commission for a civilian monitor because the investigation involves a death.

The IIU, Manitoba’s police watchdog organization, is responsible for investigating all serious incidents involving police.