A man convicted of second-degree murder for throwing another man off an Ottawa bridge 19 years ago has been found dead in his prison cell in Laval, Que.

Jeffrey Lalonde, 36, was pronounced dead shortly after 3 a.m. Monday morning at the medium-security Leclerc institution, the Correctional Service of Canada said in a news release.

Quebec provincial police are investigating the circumstances that led up to Lalonde's death in collaboration with the Correctional Service of Canada and the coroner's office.

Lalonde had been at the penitentiary since 1990 serving a life sentence for second-degree murder, attempted murder and assault in the August 1989 slaying of Alain Brosseau, a waiter at the Château Laurier hotel.

Lalonde and two accomplices killed Brosseau because they thought he was gay, which he was not.

The murder followed a summer of gay-bashing incidents around Major's Hill Park in downtown Ottawa and led to the creation of the city's hate-crime unit, the first in Canada.