A manhunt was launched after former undertaker Martyn Hughes, 50, failed to return to Sudbury Open Prison, near Derby, on Sunday.

The jail was at the centre of a political row earlier this year over the use of open prisons after 11 inmates went missing in the month of June alone.

Hughes was given three life sentences in 1996 for the murders of his two stepchildren and the manslaughter of his wife.

Derbyshire Police said Hughes was found dead in his car on a secluded farm track near Belper, Derbyshire.

"At this time it would appear Mr Hughes committed suicide and there are believed to be no suspicious circumstances," said a spokesman. "Inquiries are ongoing and next of kin have been informed."

A total of 78 prisoners absconded from Sudbury last year. The record drew criticism from shadow home secretary David Davis, who accused ministers of putting the public in danger.

A Prison Service spokesman said: "The numbers of absconds from prisons is at its lowest level in the last 10 years, despite an increasing population. Public protection is paramount and all prisoners located in open conditions have been rigorously risk-assessed.

"Open prisons are the most effective means of ensuring prisoners are tested in the community before they are released. To release prisoners directly from a closed prison without the resettlement benefits of the open estate would undoubtedly lead to higher levels of post-release reoffending."

Hughes was jailed for strangling his wife, Deborah, with a tie before murdering stepsons James Brackhahn, seven, and six-year-old Matthew Brackhahn while they slept.