Thames Valley Police are searching for an escaped prisoner with links to Peterborough.
Ben Young, aged 31, absconded from HMP Spring Hill in Buckinghamshire on Friday between 8pm and midnight.
Young is described as a white man, around 6ft 1ins tall, of slim build with black hair.
He is known to have links to Peterborough and Norwich.
Young was serving a sentence for robbery.
Investigating officer Detective Sergeant Dale Price, based at Aylesbury police station, said: “We are appealing for the public’s help in tracing Ben Young.
“If you see him, we would ask that you do not approach him, but call 999 instead.
“If anyone has any information relating to the whereabouts of Young, please call police on 101 quoting reference 43190148946’or make a report online.
“Alternatively, you contact the independent charity Crimestoppers anonymously on 0800 555 111.”