Tunisia has extradited former Libyan leader Muammar Gaddafi's prime minister to Libya.
He is the first senior official to be returned for trial under Libya's transitional leadership.
A spokesman for Tunisian President Moncef al-Marzouki said the President had not authorised any such handover.
Mr Mahmoudi served as Libya's prime minister from 2006.
When rebel fighters took Tripoli in August last year he fled to neighbouring Tunisia.
It is thought that his extradition could establish a precedent for other countries that have given refuge to or arrested members of Col Gaddafi's old entourage.
Libya's government and the International Criminal Court, which charged Col Gaddafi's son Saif al-Islam in June for crimes against humanity, have argued for months over where he should be tried.
