A Co Tyrone man wanted over a gangland murder at a Dublin hotel had stayed overnight in preparation for his alleged role in the shooting, a court has heard.
Gardaí investigating the killing of David Byrne also claim Kevin Murray can be "clearly identified" on CCTV footage.
Details emerged as the 46-year-old was refused bail in his fight against being extradited to face charges over his alleged central part in the murder.
Murray is suspected of being the person known as 'Flat Cap' who was seen running from Regency Hotel shortly after the gun attack.
He was detained at his home in Townsend Street in Strabane on Monday under a European Arrest Warrant issued by authorities in the Republic.
Byrne, a 34-year-old father-of-two from the Crumlin area, was shot dead on February 5 when masked men dressed as Garda officers opened fire with automatic guns.
His killing ignited a deadly feud between members of the rival Kinahan and Hutch gangs.
Murray is wanted in connection with alleged offences of murder, possession of a firearm with intent, and possession of a firearm in suspicious circumstances.
He was not brought to Belfast Recorder's Court for yesterday's ruling on his bid to be released from custody.
Setting out reasons for denying bail, Her Honour Judge Patricia Smyth referred to evidence contained in the arrest warrant.
She said it identified Murray as an alleged part of the gang involved in the murder of Byrne.
The warrant stated: "Following examination of CCTV footage and from photographic evidence obtained, the requested person was clearly identified by several members of An Garda Siochana."
Further identification was said to have been provided by other witnesses, including several members of the PSNI.
Although Murray's home was searched in February, he has not made himself available to investigating gardaí, the court heard.
He has made it clear that he will only take part in an identification procedure in Northern Ireland.
Referring again to the warrant, Judge Smyth said Murray allegedly stayed overnight at the Regency Hotel.
"The warrant alleges this was in preparation for his role on the murder the following day," she said.
Another man, 24-year-old Patrick Hutch of Champions Avenue in Dublin, has already been charged with the murder.
During yesterday's hearing it was claimed that he was a second member of the gang, acting with Murray.
Counsel for the southern authorities opposed the Strabane man's bail application due to the risk of flight.
Murray's legal team argued that his deteriorating health, which has led to his reliance on a walking aid and undergoing brain scans amid fears he may be developing multiple sclerosis, meant there was no chance of him absconding.
His brothers, who attended court for the hearing, were also prepared to put up a £10,000 cash surety.
But Judge Smyth held that Murray's attitude to the authorities was "highly relevant" to concerns he could flee.
She accepted he currently has significant physical impairment for currently unexplained reasons, but refused bail.
The judge stressed that a full hearing of the extradition case must be completed "in the very near future".
