Kevin Murray, aged 46, was identified by several people at the crime scene at the Regency Hotel in February, a barrister told a Belfast court.
He was arrested by police on Monday evening at a house in Strabane, Co Tyrone, on suspicion of murder and firearms offences after a European arrest warrant was issued by gardaí.
David Byrne, 33, was gunned down and two others were injured during the attack in February.
Stephen Ritchie, a barrister who represented the Irish authorities, said: “These are serious offences. Three charges arise out of events on February 5 last at the Regency Hotel, Drumcondra, in Dublin, when David Byrne was murdered.
“This man is alleged to have played a central part in the offence.”
Bail was refused by Belfast recorder Patricia Smyth, pending the provision of medical evidence. Doctors believe Mr Murray may be suffering from multiple sclerosis; he was helped into the dock by two prison officers and a mobility aid.
Mr Ritchie said: “We know in the warrant there is reference to the investigation being conducted with Garda Síochána CCTV footage being examined. Identification of this man was made by several people at the scene.”
According to the arrest warrant, a separate search of a property in Strabane resulted in a number of items being seized as evidence, said Mr Ritchie.
“He is not at all keen to assist the Garda Síochána in the investigation of these very serious offences,” said Mr Ritchie.
The lawyer told the court Mr Murray was arrested at Townsend St, Strabane, where he has been living. His father also lives in the town.
He is unemployed and separated from his wife, said Mr Ritchie, insisting Mr Murray posed a risk of flight from the jurisdiction.
“You can see that there is an element of disability to this man but nonetheless that does not mean that he could not be removed from the jurisdiction.”
Mr Murray’s lawyer, Des Fahy, said his client had been living openly in Strabane since February and had been in contact with police offering to undergo an identification procedure. He also met officers in relation to his personal security.
Mr Fahy said his client claimed the gardaí had conducted “surreptitious identification” of him when he visited a PSNI station in Strabane.
Mr Fahy said: “He is fully engaged in this process and will challenge the application (for extradition) that is being made.”
The barrister offered a surety from family members worth £10,000.
Mr Murray was remanded in custody to appear again at Belfast Recorder’s Court on Friday.