Tripoli - Tunisia extradited deposed Libyan leader Muammar Gaddafi's former prime minister on Sunday, said officials in Tripoli, making him the first senior official to be returned for trial under Libya's transitional leadership.

In Tunisia, there was confusion among officials over who authorised the extradition.

Libyan interim Prime Minister Abdurrahim El-Keib told reporters on Sunday that the Justice Ministry was holding Al Baghdadi Ali al-Mahmoudi in prison.

"The suspect is in the custody of the judicial police as per an arrest warrant ordered by the prosecutor general's office charging him with committing crimes against the Libyan people," said Keib.

A Reuters team visited Mahmoudi, 62, late on Sunday in his heavily guarded prison but authorities did not allow any interviews or interaction with the former prime minister.

Wearing a white traditional Libyan robe and clutching a cane, the bearded Mahmoudi was helped into an office in the prison by a number of policemen.

Sitting silently in a chair flanked by his guards, Mahmoudi looked exhausted and weak, his hair dishevelled, his eyes fixed on a news programme on a television in the room.

"A team led by the military's Chief of Staff, a member of the judicial police and a medical doctor flew to Tunis in a helicopter where authorities handed over Mahmoudi according to an official agreement with Tunisia's government," the general manager of Libya's prisons Khaled al-Shareef told Reuters.