Harold Brown, 35, was being treated for an undisclosed condition in hospital when he fled from the premises around 2pm.

The South Coast Register understands Brown was being treated in a ward area and was under the guard of Corrective Services staff when he asked to go to the toilet.

It is believed once inside, he tied his t-shirt to the door handle and a nearby sink to stop officers from gaining entry, then removed the rubber around a window before climbing out and escaping.

Brown was in custody over the alleged attempted armed robbery of a taxi driver at Nowra Hill on May 31. He had been due to reappear in court on September 20.

A Correctives spokeswoman on Wednesday confirmed an inmate had escaped while under the guard of prison staff.

The spokeswoman said it was the first time an inmate has escaped from Shoalhaven Hospital.

Police officers responded immediately, searching surrounding streets and bushland on Monday afternoon with help from PolAir and the NSW Police Dog Unit, but Brown could not be found.

Meantime, Correctives Services said it would launch an investigation into the incident.

“Corrective Services NSW considers the safety of the community as paramount when transporting inmates,” the spokeswoman said.

"Inmates are taken to hospital only when they can’t be treated on site, and this is often based on the seriousness or type of their injuries."

The Register also sought to confirm whether Brown was handcuffed at the time of his escape, however Corrective Services did not provide an answer.

The incident comes on the back of an announcement by the NSW Government in August that it planned to put an additional 360 beds into the South Nowra-based jail.

The prison has a population of around 600 inmates.

Police are warning the public not to approach Brown if they see him, but to phone Triple-0.

He is described as Aboriginal or Torres Strait Islander in appearance, 170-175cm tall with a medium build and black hair. He was last seen wearing underwear or green shorts and no shirt.

Anyone with any information regarding Brown’s whereabouts is asked to contact Nowra Police on 44219699 or Crime Stoppers on 1800 333 000.

South Coast Register