John Bowden, 51, failed to return to HMP Noranside in Angus on Thursday.

Police said Bowden, who was last seen in the nearby town of Forfar, was being tested in "open conditions" when he absconded.

Bowden, who is originally from south London, was given a life sentence in 1982 at the Old Bailey after being convicted of murdering park-keeper Donald Ryan.

Tayside Police are examining CCTV footage and working with British Transport Police and other forces in a bid to trace him. He was last seen near the Tesco store in Castle Street, Forfar. A Scottish Prison Service spokesman said the public should not approach Bowden.

Bowden, who was due to be considered for parole later this month, was originally jailed in England, after being ordered to serve a minimum of 25 years in prison for the murder of Mr Ryan.

With two accomplices, Bowden lured Mr Ryan to a flat to rob him and them mutilated him while he was still alive using a handsaw, electric carving knife and a machete.

Parts of Mr Ryan's body were hidden on waste ground and streets near the flat in Camberwell and his severed head was stored in a fridge before being dumped in a dustbin.

In 1992, while being held at Maidstone jail in Kent, Bowden went on the run during a compassionate visit to his sick father.

He was later recaptured and transferred to Scotland in 1995 where he held at a number of jails before being transferred to Noranside in October 2007.