The Police Service of Northern Ireland (PSNI) faces legal action after refusing to remove a banner referring to the shooting of four men in 1991.

Lawyers at Belfast firm KRW Law say police acted unlawfully by declining to remove a banner in memory of UVF man Billy Wright which appeared in Dungannon, Co Tyrone.

The banner carries the quote “I would look back and say Cappagh was probably my best”, in reference to four men - Dwayne O’Donnell, Malcolm Nugent, John Quinn and Thomas Armstrong - who were killed at Boyle’s Barr in Cappagh in March 1991.

Solicitor Darragh Mackin of KRW Law is acting for the family of the late Thomas Armstrong.

He told The Irish News: “The arguments advanced in support of the position adopted by the PSNI in this instance are unlawful, irrational and or disproportionate and in contravention of our clients’ rights pursuant to articles 3 and 8 of the European Convention.”

PSNI Assistant Chief Constable Stephen Martin said the force received legal advice which said there “was no contravention of the law, as distasteful as was”.

The family of Malcolm Nugent has challenged the PSNI to publish its legal advice.

However, a police spokesperson said: “Legal advice provided to the Chief Constable by PSNI’s Legal Services Branch is subject to legal professional privilege and cannot be disclosed to the public.”