LONDON/TRIPOLI (Reuters) - Muammar Gaddafi is believed to be hiding near the western town of Ghadames near the Algerian border under the protection of Tuareg tribesmen, the Libyan official leading the hunt for the deposed leader said.
"One tribe, the Tuareg, is still supporting him and he is believed to be in the Ghadamis area in the south," Hisham Buhagiar, a senior military officer in Libya's new leadership, told Reuters by telephone late on Tuesday.
Buhagiar said Gaddafi was believed to have been in the southern town of Samnu a week ago before moving to Ghadames, which lies 550 km (345 miles) southwest of Tripoli.
He said Gaddafi's son Saif al-Islam was in Bani Walid and another son, Mutassem, was in Sirte, the family's hometown.
"They are both thinking about leaving Libya maybe to Niger," Buhagiar added.
Sirte, one of the last bastions of support for Gaddafi, is encircled by forces of Libya's ruling National Transitional Council (NTC) and under bombardment from NATO warplanes.
Taking Sirte, 450 km east of Tripoli, would bring the NTC closer to gaining control of the entire country, a goal that has eluded it more than a month after its fighters seized the capital.
Buhagiar said most tribes in the south were against Gaddafi except for the Tuareg, who still supported him.
"There has been a fight between Tuareg tribesmen who are loyal to Gaddafi and Arabs living there. We are negotiating. The Gaddafi search is taking a different course," Buhagiar said, without elaborating.
Gaddafi's daughter Aisha, her brothers Hannibal and Mohammed, their mother Safia and several other family members fled to Algeria in August and have lived there since.
Tuaregs, nomads who roam the desert spanning the borders of Libya and its neighbours, backed Gaddafi and view with suspicion the NTC that is now in power.
Many Tuaregs back Gaddafi because he supported their rebellion against the governments of Mali and Niger in the 1970s and later allowed many of them to settle in southern Libya.
Tuareg tribes are important to regional security because they have huge influence in the vast, empty desert expanses of the Sahara which are often exploited by drug traffickers and Islamist militants as a safe haven for their operations.
In Tripoli, an NTC official said forces seeking Gaddafi were focusing their attention on the Algerian and Niger borders.
"The south gives him access to the borders into Africa," the official said.
The official said several huge and heavily armed convoys of vehicles had been spotted crossing the borders out of Libya since the fall of Tripoli, but Gaddafi was not believed to have been in them.
On Wednesday, a senior NTC officer said his fighters, on entering Sirte port two days ago, had found and seized a helicopter hidden under camouflage that appeared to have been made ready for a swift departure.
He said he suspected the helicopter was assigned for the use of a senior official of the ousted Gaddafi government, possibly one of Gaddafi's sons.
On Sept 22, Libya's interim rulers said they had further consolidated their control over Sahara desert towns that had been among Gaddafi's last strongholds, and said Gaddafi himself was running out of places to hide.
Until then some parts of Sabha, a traditional southern base for Gaddafi's own tribe about 800 km (500 miles) south of Tripoli, had been occupied by fighters loyal to him.
Colonel Ahmed Bani, an NTC military spokesman, said on Sept 22 that the manhunt for Gaddafi was drawing closer to its target.
"There is no whole tribe or city on Gaddafi's side," said Bani. "I'm asking everyone in the south who has any news about the tyrant or his loyalists...to notify the legal bodies about them."
"We are doing our best looking for the tyrant. There is some news here and there that he ran away from Sabha to another place but it cannot be confirmed."
Interest in the Ghadames area as a possible hiding place for Gaddafi loyalists rose this week after the interim government said militias loyal to Gaddafi had attacked Ghadames on Sept 24 but were pushed back.
Bani said these groups were related to Khamis Gaddafi, another of Gaddafi's sons. Bani said some pro-Gaddafi militias were using the area "to hide in" but did not elaborate.
Khamis has been reported dead on several occasions. There is no confirmed information about his fate.
Editing by Alistair Lyon