TEMPO.CO, Jakarta - Fanatics from the Islamic State terror group have beheaded one of their own commanders after accusing him of being an MI6 agent, according to reports.

Abu Ubaida Almaghribi, head of IS security in Aleppo, northern Syria, was once in charge of a prison where American journalist James Foley and other Western hostages were held.

But he has now been executed after fellow extremists accused him of passing on information about IS activities to the UK.

Abu Ubaida is believed to be a Dutch national of Moroccan descent, although his real identity is unknown. IS claimed he was executed a day after video footage of Mr Foley’s beheading emerged on YouTube.

A former IS prisoner last year told Belgian state prosecutors that Abu Ubaida was in charge of security when he and Foley were held there last year.

Last night the Foreign Office refused to comment on the claims, circulated by Moroccan and Jordanian news agencies.

A security source said: 'In the past, other extremist groups and states have made claims of spying as a justification for executing one of their own'. He added that the IS message may have been passed on to the local media by a third party.

A report by Moroccan news outlet Alyoum24 said: 'Ubaida Almaghribi, who is originally from Morocco, and served as the head of intelligence services of the ISIS organization in Aleppo, Syria, was beheaded after being accused of reporting information on the activities, movements, and plans of ISIS to the UK'.

Morocco World News stated: 'ISIS militants reportedly beheaded a group of prominent leaders including Abu Ubaida Almaghribi, because of doubts regarding their allegiance and work for foreign entities'.

Mike Doran, a Middle East expert at the Washington-based Brookings Institution, said the alleged execution was a sign of 'nervousness' within IS’s higher ranks.

FAIZ NASHRILLAH | MAIL ONE