Artemis Sorras, the fugitive leader of a fringe ultranationalist movement called Convention of Greeks, has been arrested on an outstanding warrant.
Sorras, who was arrested in southern Athens, has been convicted to eight years in prison for embezzlement. It was not clear what crime his arrest on Saturday was related to.
Police sources said they had been tipped off to the fugitive's whereabouts and had him under surveillance.
Sorras had reportedly grown a beard to hide his identity and had fashioned something of a safe room in the house where he was hiding out to evade capture.
Prior to his run-in with the law, he claimed to have enough money to pay off the entirety of Greece's public debt and that of every citizen in the country.