But authorities are also maintaining their position of not releasing the names of absconders — despite politicians’ calls — because it would breach their right to privacy.

Tayside Police revealed there are currently four prisoners from Castle Huntly, near Dundee, and Noranside in Angus who have been missing since before the start of last year.

They include a 51-year-old who was serving a life sentence, with a minimum of nine years, for murder. He escaped in May 2005.

Athough he has not officially been named, it’s understood he is Roderick George McDonald, who was jailed for killing his wife Elizabeth.

Former soldier McDonald, from Edinburgh, was sentenced at the High Court in 1993.

He was dubbed ‘the kinky killer’ after the court heard he strangled Elizabeth (36) for denying his pleas for three-in-a-bed sex with his male lover.

The other long-term escapees include a man serving a six-year sentence for attempted murder, who was 27 when he vanished in June 2005.

The longest absentee — on the run for more than two and a half years — is a man in his 20s serving five years and three months for assault to severe injury and robbery.

Police are also investigating the disappearance in October 2005 of a 40-year-old man who was jailed for three years and 10 months for assault to severe injury.

It emerged earlier this month that, as a result of a policy operated by the Scottish Prison Service and police nationally, the public has no right to know who the law-breaking prisoners are.

Prison chiefs said they believed the privacy of people who illegally leave jail before the end of their sentence outweighs the public interest.

It was also argued that the public have no part to play in the tracing of prisoners who go on the run, including those who have evaded recapture for over a year.

Assistant director of prisons Derek McGill instead gave an unqualified assurance that, as a result of the assessment process, “prisoners who have absconded from open prisons do not pose a serious risk to the public.”

Absconding from the open estate has rocketed in the last 12 months, and police confirmed there were eight prisoners missing from Castle Huntly and four from Noranside.

Police said 64 cases of absconding were reported to them during 2006, with 49 at Castle Huntly. The SPS said there had been a rise, but also noted the increased population at the Carse of Gowrie institution.

Tayside Police lead the hunt for prisoners who go missing from the two jails.

“Generally, such inquiries will be allocated to a CID officer who will undertake all relevant checks and inquiries,” said a spokeswoman. “Where prisoners are missing for a lengthy period, consideration will be given to publishing the details in the Police Gazette (a national police information system).

“The depth of inquiry and the efficiency with which it is carried out will be progressed according to the assessment made of the person at large.

“There are no boundaries, and police will follow up all relevant intelligence and inquiry avenues in order to trace an individual.”