Mahmudi, one of the most senior members of the former Libyan regime to have been detained to date, was sentenced to six months in prison for illegal entry, a Tunisian justice ministry spokesman told AFP.

Baghdadi, who was arrested yesterday, "appeared before the state prosecutor in Tozeur (430 kilometres south of Tunis) and sentenced to six months in prison with immediate effect," Kadhem Zine el Abidine said.

Interior ministry spokesman Hichem Meddeb said Mahmudi "was arrested by security forces with two men Wednesday near Tamaghza at the border with Algeria."

He said the three men did not have a visa in their passports but he was unable to say exactly when and where they had crossed the border.

On September 7, another member of ousted Libyan leader Moamer Kadhafi's inner circle, Khouildi Hamidi, was briefly detained at Tunis airport for illegal entry.

Since Kadhafi's 42-year-old regime started collapsing under the rebellion's pressure, many senior officials in his entourage have defected or fled, often transiting through neighbouring Tunisia.

Tunisia, also ruled by an interim administration since the shock January ouster of dictator Zine el Abidine Ben Ali that started the Arab Spring uprisings, officially recognised the NTC last month.

The NTC has said it wants to try former regime officials in Libya.