Mr Wright is a traditional unionist - but yet he went to Dublin to enlist the support of the Irish Government. British Government Ministers in Northern Ireland had refused to meet him.

He was seeking answers to questions about how his son was murdered by an INLA gunman while imprisoned in one of Europe's most secure prisons.

A BBC Northern Ireland Spotlight investigation into the circumstances of Wright's murder questions whether the INLA gunmen could have carried out their attack unaided.

The questions centre on how INLA gunmen were able to sneak out of their wing, which they shared with the LVF, and cross the roof of the block undetected by prison staff.

A question has also been raised about how two rival groups not then on ceasefire could be accommodated on the same wing.

The fact that a security camera covering their route was not working on the day, 27 December 1997, has led to allegations of official collusion.

Another factor is that a list containing LVF prisoners expecting visits on the day of Wright's murder was inadvertently shown to INLA prisoners.

The Spotlight programme also contained allegations that activities such as drug taking, test firing of guns and the digging of elaborate underground tunnels with electrical lighting went on in the prison.

'Blind spot in security'

These allegations have been discounted by prison authorities who have only admitted that there were blind spots in the prison security on the day Wright was killed.

Wright formed the LVF after the UVF declared its ceasefire

The programme also probed claims that Wright, who succeeded the notorious UVF terrorist Robin "The Jackal" Jackson as local commander, was involved in the murders of up to 40 people.

Also uncovered in the programme are details about Wright's involvement with drugs and drugs dealing. He always denied this but traces of cannabis were found in his blood at his post mortem.

Known as 'King Rat'

Known as King Rat, Wright was a central figure in the Drumcree dispute. He was known to be the ringleader of a breakaway loyalist dissident group, the LVF, following the declaration of the UVF ceasefire in October 1994.

Subsequently he held a public rally, in which prominent loyalists including Portadown Orange Lodge Grand Master, Harold Gracey and DUP assembly member the Rev William McRea joined him on the platform.

At this rally, he declared that he had received a death threat to move out of Portadown. He refused. Not long after he was convicted and imprisoned in the Maze for witness intimidation.

Inquiry calls by nationalists

The circumstances of Wright's murder while in custody have sparked calls from many quarters for a proper inquiry. Among the supporters of calls for a public enquiry into Wright's death are Sinn Fein and the SDLP.

"Where questions have been raised, answers should be given," said Alex Attwood, a West Belfast SDLP assembly member.

"The nationalist community knows about the need for inquiries and can appreciate why Billy Wright's father is making the call."