Gaddfi son says "We have broken the backbone of the rebels and they had fallen into a trap we gave them a hard time so were winning".
He turned up in a government vehicle at a hotel held by loyalists a day after the rebels claimed that they had detained him, report said.
Fighting in Tripoli has restarted with the sounds of gunfire and grenades and both sides say they control most of the capital.
The rebels met strong resistance from pro-Gaddafi forces as they continued their push on Monday.
Rebel fighter claimed that they were in control of 95% of the city but the BBC reporter in Tripoli says it is still unclear who is winning the battle for the capital
Gaddafi forces have been reinforced and some rebel supply lines into the city seem to have come under attack. It is clear loyalists are fighting back in some areas and many casualties are being reported.
BBC