Francis Boucher, son of notable former Hells Angels leader Maurice "Mom" Boucher, has been accidentally released from Bordeaux Prison in Montreal.

A provincial Security Ministry representative said that Boucher, 39, tricked guards into allowing him to leave custody on Monday at 11 a.m., even though he was only due to be released at the end of May.

The representative did not specify how Boucher tricked the guards.

Boucher was serving 117 days in jail for uttering death threats against police officers.

Meanwhile the provincial minister of Public Security is outraged by Boucher's release, and Lise Theriault said it was a completely unacceptable event and she wants to get to the bottom of it.

"Each time there is an incident inside a detention centre an investigation is automatically triggered to determine the process that people took, to see what people did, to see what we missed to determine if there is something we can do to improve the monitoring of the comings and goings in detention centres," said the minister.

One guard has been suspended with pay pending the outcome of that investigation.

Thierry Lariviere, a spokesman for the labour group that represents the guards, confirmed the suspension and said the union wouldn't comment further.

Boucher was in jail on charges of threatening police last December. He had a previous 10-year conviction for gangsterism, conspiracy to commit murder and drug trafficking following a major roundup in 2001.

Francis Boucher stands 5'9" (1.8 m) weighs 165 lbs (75 kg), has green eyes and salt-and-pepper hair.

Anybody who spots him is asked to call 911.

-With a file from The Canadian Press