There is growing outrage about the inadvertent release of an accused bank robber into Metro Vancouver, but prison officials are providing few answers about what happened.

Dean Richard Zastowny, who has a lengthy criminal history throughout the region that includes violent offences against police, was recently let out of a pre-trial facility in Surrey by mistake.

The 47-year-old has been on the loose since at least Saturday, but how or why he was allowed to leave remains a mystery. Surrey city councilor Bruce Hayne said the incident is particularly troubling because the pre-trial facility is located in a densely populated residential area in Newton.

"He could be anywhere," Hayne said. "It is concerning that this type of thing could happen, and whether it's a clerical error or whatever it may be we need to understand what happened and take steps to make sure it doesn't happen again."

But BC Corrections, the agency in charge of Zastowny's incarceration, has so far been tight-lipped about what went wrong despite repeated requests for information from CTV News. Public Safety Minister and Solicitor General Mike Farnworth had little to offer either when asked about the incident Tuesday.

"There's a full investigation underway into what took place and it's being conducted by an individual not associated with that particular facility," Farnworth said.

The minister said prisoners are sometimes released from custody by mistake, but it is "very rare."

When police first revealed that Zastowny was on the lam, he was only described as being unlawfully at large, with no indication that he was accidentally let go. Police did warn that he is considered armed and dangerous.

BC Corrections only acknowledged he’d been inadvertently released when contacted by CTV News.

"Given the ongoing investigations, we are unable to release any further details at this time," spokesperson Cindy Rose said in an email Monday.

Mike Morris, solicitor general critic for the BC Liberals, told CTV News he would expect officials to be more forthcoming.

"I like to see our institutions as transparent as possible, so I'm surprised they haven't at least spoken publicly about this," Morris said.

Zastowny's criminal record includes convictions for assaulting a peace officer, uttering threats to cause death or bodily harm, robbery and theft over $5,000.

He was arrested in November in connection with a number of bank robberies in Burnaby and Abbotsford. Few details of the robberies have been shared with the public, but surveillance video from one of them shows a man hopping over a bank counter then holding a knife to a teller's throat.

Zastowny is described as white, 6-1 tall, 215 lbs. with blue eyes, brown hair and tattoos, including a full sleeve on his right forearm featuring a skull and a snake.

Anyone who sees him is encouraged to call 911 immediately. Police caution he could be carrying a weapon and should not be approached.

With files from CTV Vancouver's Penny Daflos