A maximum security prisoner has escaped from Goulburn Correctional Centre after tying bed sheets together to climb over a jail wall.

Stephen Jamieson, 28, had been in segregation after being identified as a suspect over the discovery of a man-made hole in the floor which was found in the prison earlier this month.

Jamieson was last seen at about 12:50pm today and was wearing prison greens at that time.

• ‘No way’ to arrest Monis
• PM reads ministers ‘riot act’

He is serving 12 years in prison for armed robbery and officers said anyone who sees him should contact triple-0 immediately.

Police said Jamieson is described as being of Caucasian appearance, 177cm tall, of thin build with a fair complexion and brown eyes.

NSW Corrective Services Commissioner Peter Severin said the prisoner escaped from a small secure exercise yard that is attached to each segregation cell.

“He was able to get out of that exercise yard and then he had a range of bed sheets that he tied together and was able to swing them over the wall to then effect his escape by scaling that wall,” he said.

Stephen Jamieson, 28, escaped from Goulburn Correctional Centre on Tuesday.

Jamieson was placed into segregation after a 60 centimetre man-made hole was discovered inside a workshop at the prison.

The cavity, with a 40 centimetre by 18 centimetre wide entrance, was found under a cabinet during a search of the furniture workshop at the jail in the southern tablelands.

The Department of Corrective Services said the cavity was more than 100 metres away from the outside wall of the prison.

An investigation was launched into whether inmates had been trying to dig a tunnel after the hole was found.

The Mayor of Goulburn said at the time there was no risk to public safety and the maximum security facility at the prison was the “strongest and most secure prison facility in NSW if not Australia”.

Commissioner Severin said he could assure the community that the correctional system was safe.

“[The security] does provide community safety; last year we had the lowest ever recorded rate of escapes, they were all from open custody,” he said.

“It is a very serious matter, it is one that we will not only carefully investigate but certainly conduct a quite intensive security review which will involve some interstate assistance that I’m going to seek this afternoon from my fellow commissioners.”