"Carlos the Jackal" was arrested while undergoing liposuction to remove fat from around his waist, the Observer reported.

The British Sunday newspaper quoted a Sudanese doctor in Cairo as saying Carlos had been admitted to a private hospital in Khartoum and that French agents seized him after he was rendered unconscious by anaesthetic.Carlos, whose real name is Illich Ramirez Sanchez, was arrested last week in Sudan and extradited to France to stand trial for attacks authorities say he carried out during his left-wing guerrilla campaigns of the 1970s and 1980s.

The Observer said the dumpy Carlos had been admitted to a hospital run by Sudan's National Islamic Front for liposuction, a common cosmetic operation in which doctors vacuum fat out from under the skin.

But once he was anesthetised, French agents took him away.

Authorities have not said how Carlos was arrested and there has been intense speculation about who told authorities where he was and how the French government persuaded the Sudanese to extradite him.