A man alleged to have played a central part in the Regency Hotel shooting will fight extradition from the North.
Kevin Murray (46) was identified by several people at the crime scene in February, a barrister told a Belfast court.
David Byrne (33) was gunned down and two others were injured in the attack.
Mr Murray 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 Irish authorities.
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 the suspect may be suffering from MS and he was helped into the dock by two prison officers and a mobility aid.
"We know in the warrant there is reference to the investigation being conducted with An Garda Siochana and CCTV footage is being examined," Mr Ritchie said. "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, Mr Ritchie said.
"He is not at all keen to assist An Garda Siochana in the investigation of these very serious offences," Mr Ritchie added.
The lawyer said the suspect was arrested at Townsend Street in Strabane, where he has been living. His father also lives in the border town.
He is unemployed and separated from his wife, Mr Ritchie said. He said the suspect posed a flight risk.
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.
He said his client had claimed Irish police had conducted "surreptitious identification" of him when he visited a Police Service of Northern Ireland (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.