Abdessalem Jalloud, who was a former prime minister ostracized from Moamer Gaddafi's regime, had earlier been reported to have fled to rebel-held territory.
He took "a plane for Italy from Djerba airport at 3:40 am (0240 GMT)", an airport official on the resort island told AFP.
The government official said "Jalloud left Djerba airport for Italy at dawn on a Maltese plane with his family".
He could not say how many people boarded the flight.
Another government source said Gaddafi's former close aide arrived in the southern Tunisian town of Remada overnight Friday.
"He surrendered to the Tunisian army before he was taken care of by Qataris," the source said, adding that Italy may only be a stopover before Jalloud settles elsewhere.
Qatar is one of the few Arab countries that is an active partner in the international intervention against the Gaddafi regime. It also recognises the rebels' National Transitional Council and is home to the Free Libya television station which it partly finances.
In the Italian capital foreign ministry spokesman Maurizio Massari would not confirm or deny the report.
"We are verifying this information," he said.
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