A former biker-gang hit man turned informant whose testimony brought down Hells Angels boss Maurice (Mom) Boucher has been granted escorted leaves from prison.

The Parole Board of Canada today granted the temporary police-escorted leaves to Stephane (Godasse) Gagne, the former elite Hells Angels member sentenced for the 1997 killing of a Quebec prison guard.

Gagne pleaded guilty in 1998 to the first-degree murder of Diane Lavigne and the attempted murder of a second guard. He has served nearly 21 years of his life sentence.

He was also involved in the slaying of another guard, but the Crown agreed to withdraw that charge in exchange for Gagne's testimony against Boucher.

Boucher, convicted in 2002, ordered the killings of the prison employees in an attempt to send a message and destabilize the justice system.

Gagne was initially not eligible to apply for parole until he had served 25 years, but in 2015 he won the right to seek an earlier release.