"General Belgasem al-Abaaj, who we captured on Monday, said that Gadhafi had contacted him by phone about 10 days ago, and that he was moving secretly between (the oasis town of) Sabha and Ghat" on the Algerian border, said Mohammed Barka Wardugu.
Abaaj had said that Gadhafi "is helped by Nigerian and Chadian mercenaries who know the desert routes," added Wardugu, spokesman for the Desert Shield Brigade attached to the National Transitional Council (NTC).
The general was Gadhafi's intelligence chief in the southern Khufra region, where he was wanted by the NTC for many crimes, Wardugu said.
"I think Gadhafi is hiding in the Sahara region between Libya and Algeria," he said, adding that dozens of dozens of mercenaries and soldiers loyal to Gadhafi had been arrested in the south.
"We have arrested 18 Gadhafi soldiers, 300 Chadian mercenaries and today we caught 60 people of different nationalities (Sudanese, Somalis and Eritreans) in the vicinity of Zouila" southeast of Sabha, Wardugu said.
He said the region was calm following the capture of Sabha on Wednesday. Regarding the existence of concentrated uranium or yellow cake in the Sabha area, Wardugu said its existence had been known "for a long time."
"For many years, we knew that there were biological or radioactive materials stored in a military centre in the northeast of Sabha airport."We had talked to the Gadhafi regime about the danger to civilians. But they never did anything for the people of the south."
The UN atomic agency confirmed the existence of yellow cake in Libya after US news channel CNN reported that new regime forces had found potentially radioactive material.