An Islamic State suicide bomber from Britain who blew himself up in an attack on Iraqi forces this week had been given compensation for his detention in the Guantanamo Bay military prison.
Islamic State militants said Abu-Zakariya al-Britani, a British citizen who was originally known as Ronald Fiddler and then cast himself as Jamal Udeen al-Harith, detonated a car bomb at an Iraqi army base this week.
The militants also published a photograph of the smiling bomber surrounded by wires in the seat of what appeared to be the car in which he blew himself up.
The Islamic State statements could not be independently verified by Reuters but three Western security sources said on Wednesday it was highly likely that Britani was the bomber and now dead.
A spokesperson for Prime Minister Theresa May said the government was not able to verify his identity.
"There is no independent confirmation of the identity of this man who is believed to be dead in Mosul," he said. "Obviously the situation in Syria means we don't have any capacity to verify anything in Syria."
Britain reached a civil damages settlement with British former Guantanamo Bay inmates in 2010, then-Justice Secretary Kenneth Clarke told parliament at the time, but he did not disclose the size of the payouts, citing confidentiality agreements.
The Daily Mail reported that Britani had been awarded $US1.25 million (NZ$1.75 million) by the British government after claiming British agents knew or were complicit in his alleged mistreatment. May's spokesperson declined to comment on the details of any payments or whether the government had been monitoring Britani.
Britani's family, in a statement to the BBC, said their son had not received a million pounds in compensation and that they believed that figure was a group settlement, including costs and also covering other inmates.