Tripoli, Libya ? Determined to hunt down Moammar Gadhafi, Libya’s new rulers say they have dedicated a special unit of fighters to track the elusive former leader, listening in on his aides’ phone calls, poring over satellite images and interviewing witnesses.

Although leads come mostly from on-the-ground tips, help is also coming from France and other Western countries, according to a French intelligence official. Satellite-based transmission intercepts of suspicious phone calls try to pinpoint where Gadhafi might be. Small CIA teams are also assisting in the manhunt, according to former U.S. officials.

Gadhafi, who hasn’t been seen in public for months, went underground after anti-regime fighters swept into Tripoli on Aug. 21. Capturing the ousted ruler would allow the former rebels to seal their grip on the country and shut the door on the possibility of Gadhafi’s inspiring an insurgency against the new leaders.

After more than four decades under his authoritarian rule, Libyans are haunted by the question of Gadhafi’s whereabouts, and the country has been awash with rumors that have put him everywhere from deep in a bunker under Tripoli to safe in exile in neighboring Niger or Algeria. On Thursday, Gadhafi himself dismissed talk of his flight, saying in an audio broadcast that he’s still in Libya, and exhorting followers to keep fighting.

An anti-Gadhafi fighter, speaking on condition of anonymity because of the sensitivity of the matter, said revolutionary forces stormed a villa on Tripoli’s outskirts last week acting on a tip.

The fighter, who took part in the operation, said they believe Gadhafi was at the villa and escaped less than an hour before the raid through a secret tunnel. Computers were on and cups of tea were still warm, he said, indicating the occupants had just fled.

Two chefs working at the villa were detained and documents recovered, the fighter said.