The body of 55-year-old Zaki Mubarak was transferred last week from Turkey to Cairo after Ankara said last month he had committed suicide in prison.

Turkey had charged him with spying for the United Arab Emirates.

After seeing his body on its arrival in Egypt, his family said it had been badly mutilated.

“His tongue was removed and we saw marks of torture on the corpse,” said Abs Mubarak, his cousin, who is in Cairo.

He accused Turkish authorities of carrying out an “extra-judicial killing”.

Mubarak, from the Gaza Strip, had fled the enclave in 2007 after Islamist movement Hamas seized control there.

He was arrested in Turkey last month, along with another alleged spy, and later formally charged with espionage, according to Turkish state news agency Anadolu.

Turkey said at the time it had arrested two men on charges of “political, military and international espionage” as part of an investigation into alleged spying by the UAE.

The previously unidentified suspects reportedly confessed to spying on Arab political exiles in Turkey.

Turkish media have speculated he was allied to Mohammed Dahlan, a UAE-based former supporter and now rival of Palestinian president Mahmoud Abbas.

But his family have denied he had any relationship with Dahlan’s movement.

His brother, Zakaria Mubarak Hasan denied claims that he had committed suicide while in prison in a video published on Facebook, claiming he had been “killed”.

Ankara has been investigating claims the two detainees were linked to the killing of Jamal Khashoggi, a Saudi journalist whose killing in the country’s Istanbul consulate last year sparked a diplomatic crisis.

His family deny the allegations.

Turkey’s justice ministry has rejected claims Mubarak was tortured.

Mubarak’s cousin said the autopsy was due to be finalised by the end of Tuesday before the body would be returned to the blockaded Gaza later this week.