Moussa Ibrahim, the mouthpiece of the Gaddafi regime, was captured last night outside the birthplace of the former dictator, according to commanders of the National Transitional Council's forces.
There were also unconfirmed reports that Ibrahim was dressed as a woman as he attempted to flee Sirte, which has been the scene of heavy fighting for several days.
A commander for the NTC's Zintan brigade said: "Moussa Ibrahim was captured while driving outside Sirte by fighters from Misurata." Ibrahim became a fixture on news bulletins from the first week of the uprising, lecturing the foreign media from a conference room at the Rixos Hotel in Tripoli on the iniquities of Nato and the West.
Like Col Muammar Gaddafi, his whereabouts had been unknown until yesterday.
His capture came as forces loyal to the transitional government seized the airport in Sirte, moving through the partly destroyed buildings tearing down symbols of the Gaddafi era.
Meanwhile, an Interpol arrest warrant was issued for Gaddafi's son Saadi, who escaped to Niger, but the country's prime minister there said he would not be extradited.