Hundreds of lives were put at risk at Sutton library after the ground floor fire exit was illegally locked, a Sutton Guardian investigation has revealed.

Fire safety investigation officers called to the library on Monday, March 8, forced managers to unlock a fire exit on the ground-floor and ordered a full investigation into fire safety in the building.

A concerned resident first noticed the problem in January and repeatedly asked managers to unlock the door pointing out the potential loss of life.

The resident secretly filmed the hazard and alerted London Fire Brigade, who spent one-and-a-half hours assessing the library on Monday.

The resident claimed the fire exit was locked all day on Mondays and on Friday evenings when the rest of the library is closed.

He said: “Staff told me it was to stop people getting to the stairwell leading to other floors. It makes me angry that people’s lives were being put at risk for no good reason.

“I asked managers to unlock the exit three times and they refused. I’m pleased London Fire Brigade recognised the problem.”

Former Sutton firefighter Councillor Tony Shields said: “It is disgraceful and there is no excuse for endangering lives in that way.

“Fire spreads incredibly quickly especially in places like libraries, which are full combustible materials. Someone could have lost their life getting to an exit, which turned out to be locked.”

The secret film also shows a locked fire door leading to a fire exit, although London Fire Brigade said this was not illegal.

One of the officers said the case could have been referred to a magistrates’ court and the council could have received a fine if library managers had ignored the fire brigade’s advice and refused to unlock the exit.

Councillor Stuart Gordon-Bullock said he was going to ask the council to conduct an investigation into the issue.

He said: “It is extremely disappointing, particularly as management were made aware of the situation several times.”

A Sutton Council spokesman said: “The safety of library visitors and staff is paramount and we took action to follow the fire brigade’s guidance.

“During their visit, they advised us to open another fire exit in the library on Mondays, when only the ground floor is open, and we were happy to.”