The president of the Workers' Party, Sean Garland, has been released on bail by a court in Belfast, pending his possible extradition to the United States on counterfeiting charges.
The court heard the 71-year-old had been arrested last night as he attended the party's annual conference at a hotel in the city.
Members of the Workers' Party staged a protest this afternoon outside Belfast City Hall in support of Mr Garland.
The US government is alleging that since the early 1990s, he and others bought, transported and either passed as genuine or re-sold large quantities of high quality counterfeit $100 dollar notes.
The US authorities also allege that Mr Garland arranged with North Korean agencies for the purchase of quantities of notes and enlisted other people to disseminate the money within the UK.
A warrant for his arrest and possible extradition was issued on 19 May. A defence lawyer said Mr Garland 'strongly protested' his innocence.
It is understood the US authorities have 65 days in which to lodge the extradition papers with the court.