Police are appealing for help to find a prisoner with links to Northampton after he absconded from Springhill open prison in Grendon Underwood last week.
Mark Merchant, 40, escaped at about 9.20pm on Thursday, May 4, and is known to frequent Northampton and the Croydon area of London and is still at large, a spokeswoman for Thames Valley Police said.
He had been in prison for committing arson recklessly, harassment and common assault.
But Merchant had been jailed in 2007 for brandishing a 15 ins machete as he chased a group of youths from Victoria Gardens, Northampton, to Bridge Street.
He is white, of a slim build, around 6ft 3ins tall, with short brown hair, blue eyes and has a scar on his forehead above his left eye and has a Northamptonshire accent.
When he was last seen he was wearing a grey jumper, black Adidas jogging bottoms with three stripes down the side and white Nike trainers.
Investigating officer Det Con Rachel Huggins, based at Aylesbury police station, said: “We are carrying out a thorough investigation to find Mark Merchant and as part of this investigation we are appealing to the public to come forward with any information they have.
“If you know where Merchant is or if you see him please call police on 999.
“We do not believe Merchant poses a threat to the public, however, please do not approach him instead contact police immediately.
“If you see or know where Merchant is please call 999, or call 101 with any other information quoting reference URN 19 05/05.
“If you do not want to speak directly to the police you can contact the independent charity Crimestoppers anonymously on 0800 555 111.”