A BRITISH army file relating to the McGurk's Bar bombing will not be made publicly available until 2056, a campaigner has been told.

Fifteen people died when a loyalist bomb exploded at the North Queen Street bar in Belfast in December 1971.

In the hours after the attack security forces blamed the IRA, a claim that later proved to be untrue.

Ciarán MacAirt, author of The McGurk’s Bar Bombing, Collusion, Cover-Up and a Campaign for Truth, said he made a request under Freedom of Information legislation for a file from British army headquarters in Northern Ireland relating to the death of his grandmother, Kitty Irvine.

He believes the document, held by the National Archives in London, could shed more light on the RUC's knowledge of the bombing shortly after the attack.

"There was an RUC liaison officer who worked at the army headquarters. The Chief Constable would have been aware of a log of that nature."

However, the response stated that the file is being withheld due to "health and safety" and "personal information where the applicant is a 3rd party".

It adds that the record is closed, and is not due to be opened until January 1 2056.

Mr MacAirt is due to appear at an independent tribunal hearing in London next month as part of attempts to have this and other files released.

He said: "I will be being grilled for two days, which is longer than suspects in the actual bombing were questioned for. I'll be being asked questions on a file which I haven't read but that everyone else in the court has.

"It is not justifiable that 45 years later we can't get this information. It is less to do with national security and more to do with national shame.

"The British army and police knew full well that the bar had been attacked and that it wasn't down to the people in the bar.

"They are not banking on children and grandchildren of relatives following things up."

Last week The Irish News reported on documents uncovered by Mr MacAirt which reveal that the British army knew the bomb was placed at the entrance of the bar as opposed to inside it, as was originally claimed.

The information was listed as "Not for PR", which is believed to mean it was not to be made public.

In 2011 a Police Ombudsman investigation concluded that detectives had failed to properly probe loyalist paramilitary involvement because they focused on a theory that republicans were responsible.

However, relatives were angered and launched a legal challenge when the PSNI's Historical Enquiries Team later produced a report claiming there was no evidence of bias.