The Progressive Unionist Party, political wing of the UVF, has denied that the office in Ballymoney, Co Antrim, in which a cache of arms was uncovered yesterday, belonged to the party.
In a statement issued last night the PUP said that it had vacated the premises in February 1999.
The RUC is investigating ownership of the building and whether the weapons found in it have been used by loyalist paramilitaries. No arrests have been made.
A sub-machine gun, a rifle, a stun gun and replica firearms were seized during a planned search of the Edward Street premises yesterday. The RUC also found parts of a booby-trap bomb, pick-axe handles, baseball bats, balaclavas and combat clothing.
The weapons are undergoing forensic examination.
Politicians from all parties in the North expressed concern at the arms find.
The DUP said that the early release of paramilitary prisoners should be reviewed. It urged the RUC to search all PUP offices in the North and to investigate the party's link with "punishment" attacks.
Mr Gerry Kelly, a Sinn Fein Assembly member, said that the easy access to the arms cache showed that the weapons were there to be used. However, he felt that the seizure should not be used to attack the Belfast Agreement.