Ottawa Police Chief Charles Bordeleau issued a statement Sunday, identifying the officer as Staff Sgt. Kalid (Kal) Ghadban, 43.
Bordeleau said the 22-year veteran was a well-respected and well-loved member of the city's police service.
The statement from Bordeleau said Ghadban "succumbed to injuries" Sunday afternoon after an "incident" at the police station.
Ontario's police watchdog has been called in.
The Special Investigations Unit is automatically brought in when someone dies as a result of police actions.
The statement said more information would be released when it was available.
The thoughts and prayers of those at the Ottawa Police Service are with Ghadban's family, Bordeleau said.
"Those who have worked with him know him as an excellent example of a hard-working, dedicated officer who loved his job," he said in the statement.
"The news of his death pains us all."