A man arrested by police investigating a security alert involving Minister for Foreign Affairs Simon Coveney in March has appeared in court charged with possession of firearms and other offences.
Winston Irvine, 46, from Ballysillan in north Belfast, appeared at Belfast Magistrates' Court by video link.
He was charged with possession of a firearm and ammunition in suspicious circumstances, possession of a prohibited firearm, and possession of a handgun and ammunition without a certificate.
Mr Irvine spoke only to confirm that he understood the charges against him.
The court was told police had been planning to arrest Mr Irvine about another matter on Wednesday morning when they saw him open and close the boot of his car shortly after meeting and talking to a man who parked behind him in a red van.
When his car was searched a short time later in the Shankill Road area, a PSNI detective inspector said two suspected firearms, an air gun and more than 200 rounds of ammunition were found in a leather holdall inside a plastic shopping bag in the boot.
The officer said Mr Irvine said he had not been aware of what was inside the bag.
The weapons included two 8mm blank calibre pistols, one of which the court was told had been modified and was capable of firing modified ammunition.
The ammunition included rounds for an SA80 British army assault rifle.
During a search of Mr Irvine's home in the Ballysillan area, police found a balaclava, £3,000 in cash and several items bearing the insignia of the loyalist paramilitary group the Ulster Volunteer Force.
Making an application for bail, a defence lawyer described Mr Irvine as a well known community worker and "renowned peace builder" who had been involved in the peace process and reconciliation work for many years.
Barrister Joe Brolly told the court Mr Irvine had been instrumental in helping to bring about the decommissioning of UVF weapons in 2009 and had continued work to remove some remaining weapons from circulation.
He said Mr Irvine had extensive contacts at the highest levels with the Irish and British governments as well as the PSNI, and had been due to graduate with a Master's degree in International Peace Building from Maynooth University today.
Mr Brolly said his client had believed he was taking the items "from one person to what he believed was an honest broker on the other side".
District Judge George Conner refused bail and Mr Irvine was remanded in custody to appear in court again on 1 July.
A 51-year-old man arrested in Ballymena in Co Antrim as part of the investigation remains in custody.