(CNN) -- Libya's most recent prime minister under the regime of deposed dictator Moammar Gadhafi was in Libyan custody on Sunday after extradition from Tunisia, a Libyan justice official said.
Al-Baghdadi al-Mahmoudi was handed over to prison officials in Tripoli, said the official, who asked not to be named as he is not authorized to speak to the media.
Al-Mahmoudi was arrested in September near Tamaghza, near Tunisia's border with Algeria. At the time, the Tunisian interior minister said he had entered Tunisia illegally without a visa. The ministry said he was attempting to cross into Algeria at the time of his arrest. A decision to sentence him to six months in prison was later overturned on appeal.
Al-Mahmoudi is the first high-level Libyan official to be sent back for trial.
In November, a Tunisian court rejected a request to release al-Mahmoudi and decided to extradite him despite arguments from his defense team that the lack of stability in Libya means he would not have a fair trial, according to Tunisian state news reports.
Human Rights Watch also called on Tunisia to halt al-Mahmoudi's extradition, saying the former premier is expected to face "a real risk of toruture."
Gadhafi, who ruled Libya for nearly 42 years, was toppled in a civil war last year and killed after several months in hiding.
CNN's Jomana Karadsheh contributed to this report.