SYDNEY (Reuters) - A prisoner lost some 30 pounds so he could squeeze through a hole he chiseled in a brick wall and escape from a maximum security jail in Sydney. Robert Cole, 36, who was serving time for stealing and assault, was being treated in the Long Bay prison hospital when he broke out of jail Tuesday night or early Wednesday morning. New South Wales state Corrective Services deputy commissioner Ian McLean told reporters it appeared Cole had deliberately lost weight so he could slip through the crack in the wall. "It certainly looks like it to me," McLean said on Wednesday. After squeezing through a small hole next to a window in the hospital wall, Cole scaled a wire fence crowned with razor wire and then walked along a prison wall, before jumping to freedom. There were no guards on the prison wall overnight, as jail authorities relied on surveillance cameras and sensor detectors to stop night jailbreaks. Long Bay's security manager has been stood down pending an investigation, said McLean.