Golden Dawn leader Nikolaos Mihaloliakos appeared before investigating magistrates and a prosecutor to respond to chargesof founding and participating in a criminal organisation.
Mihaloliakos has denied the charges against him.
The decision to jail the party chief was a boost for PrimeMinister Antonis Samaras' efforts to clamp down on Golden Dawnafter a party sympathiser fatally stabbed an anti-fascism rapperlast month.
Mihaloliakos was arrested on Saturday alongside other partymembers as part of the government's efforts of rein in a partyit says is a neo-Nazi criminal gang.