The video will be broadcast on Arab television stations

The video was recorded in Arabic by the British Ambassador to Iraq, Edward Chaplin.

Mr Bigley, 62, from Liverpool, was taken hostage on 16 September by the Tawhid and Jihad group, and was beheaded more than three weeks later.

He reportedly tried to flee before he was killed in Latifiya, near Baghdad, but his body has still not been found.

Latifiya has been described as a lawless area and American and Iraqi forces have recently been attempting to regain control.

'Agonising chapter'

Mr Chaplin said the video had been made with the backing of Mr Bigley's family.

"We have chosen with the family's support to release this video," he said.

"It's now over a week since we had proof of his murder."

"Everyone realises that his family has been through an enormous amount of suffering during the time since he was kidnapped.

"Now we just want to see if we can get to the end of this agonising chapter."

A telephone number was broadcast on the video, for anyone with any information on the whereabouts of the body to get in touch.