Claims that the decapitated body of murdered hostage Ken Bigley is buried near Falluja in Iraq are being followed up by the UK Foreign Office.
Ken Bigley was held captive by Iraqi militants
Osman Karahan, lawyer for suspected al-Qaeda militant Loai al-Saqa told a news conference the body was buried in a ditch at the entrance to the city.
He said Mr Saqa had been the president of an informal "court" which sentenced Mr Bigley to death.
Mr Saqa is to stand trial in Turkey over bombings in Istanbul in 2003.
The Tawhid and Jihad Iraqi militant group killed Mr Bigley, 62, of Walton, Liverpool, on 8 October 2004.
Mr Bigley had been working on an engineering project when he was kidnapped along with two Americans, Eugene Armstrong and Jack Henley, who were also murdered.
Mr Karahan did not say whether Mr Saqa actually carried out the sentence on Bigley.
He told the news conference in Istanbul, Turkey: "He took the decision. We have no information on the execution of the sentence. My client has not made an announcement on that."
The Foreign Office said: "We're following up the claims and have pursued every possible lead, whether or not the information is likely to prove accurate. We never regard a case like this as closed."
"Ever since the murder of Ken Bigley we continued to do all we can to establish the full circumstances of his death and to bring those responsible to justice".
The office added it was "too early to be specific" about how the claims would be followed up.
Mr Bigley's brother Paul told Sky News that if these claims had been made he hoped senior officials from Scotland Yard would be sent to Turkey.
"I have had some feedback that there is a couple of people from the Foreign Office that have been dispatched. I would like to think that they can assist in all the way they can to bring Ken home," he said.
Another brother, Stan Bigley, said he would not give credibility to the reports until their truth could be established by the Foreign Office.
"It's all hearsay at the moment and it's difficult to know who to believe," he said.
"I have heard these claims but I don't think anyone knows whether or not they are true. It is very frustrating."
He added that he was desperate to bring his brother's remains back to the UK for burial.
On Thursday, the Foreign Office said it was investigating claims that Mr Saqa had admitted he was one of the gang that abducted and murdered Mr Bigley.
The Guardian newspaper had reported that Mr Saqa admitted presiding over Mr Bigley's mock trial.
But the newspaper said Mr Saqa denied having any role in the Istanbul bombings in November 2003, which killed 61 people and injured more than 600 at four targets, including the British consulate and HSBC bank headquarters.
Britain's consul general Roger Short was among those who died.