A killer who went on the run from an open prison almost three weeks ago should have been in a higher security jail, his victim's family has said.

Ashley Squires went missing from HMP Sudbury in Derbyshire on Saturday, August 21 and was still at large last night.

Squires, formerly of New Parks, Leicester, was serving a 12-year sentence for knocking down and killing 61-year-old farmer Michael Boffey, in August 2005.

Mr Boffey suffered serious head injuries when he tried to prevent Squires and his brother, Frederick, escaping in his Land Rover.

Squires admitted the manslaughter charge and was moved to HMP Sudbury after serving four years of his sentence.

Mr Boffey's son, William, 46, of Burbage, said: "It would be an injustice if he is not picked up and brought back to prison.

"The people who make the decisions on whether prisoners are held in open prisons have a difficult job to do, but in this case we think they have misjudged this man."

On the day of Mr Boffey's death, Squires and his brother Frederick, both formerly of Styon Road, had been driving around the Leicestershire and Warwickshire countryside looking for cars to steal.

They targeted Grange Farm in Withybrook, near Hinckley.

Mr Boffey, who lived in nearby Burton Hastings, suffered massive head injuries when he tried to stop the brothers from driving away with his vehicle.

Ashley Squires had been jailed for three-and-a-half years in July 2003 for a similar crime. The brothers were jailed in January 2006.

Squires is white, 5ft 10in and of medium build. He has short, blond hair, green eyes and an East Anglian accent.

A Prison Service spokeswoman said open jails helped prepare offenders, such as Squires, for their eventual release.

She said: "Prisoners may be released on temporary licence providing they meet strict criteria and pass a rigorous risk assessment.

"Only those assessed as representing minimal risk of escape or risk of harm to the public are eligible."

When captured Squires is expected to be transferred to a higher security prison.

Last month the Prison Officers Association, (POA), told the BBC that numerous prisoners had absconded from Sudbury in recent years, including several convicted murderers.

POA spokesman Glyn Travis said: "The pressure on the Prison Service to fill open prison places is immense. Sudbury over the last two or three years has had a high record of absconds.

"Staff at Sudbury have constantly raised concerns about too many inappropriate prisoners being forced through the system."