The leader of Greece's far-right Golden Dawn party was jailed pending trial on charges of belonging to a criminal group, a court official told Reuters early on Thursday. Golden Dawn leader Nikolaos Mihaloliakos appeared before investigating magistrates and a prosecutor to respond to charges of 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 Prime Minister Antonis Samaras' efforts to clamp down on Golden Dawn after a party sympathiser fatally stabbed an anti-fascism rapper last month. Mihaloliakos was arrested on Saturday alongside other party members as part of the government's efforts of rein in a party it says is a neo-Nazi criminal gang.