The Government allegedly abused its power by deciding to jail Protestants without trial in the 1970s in a bid to balance mass Catholic internment, the High Court heard yesterday.
Counsel for one of the men suing over being locked up claimed there was an unlawful policy which only came to light decades later.
James Wilson has brought an action against the Northern Ireland Office, the chief constable and the Ministry of Defence.
Mr Wilson, who was arrested in 1973 and held for more than a year, is alleging assault and battery, false imprisonment and misfeasance in public office.
Lawyers for the Government yesterday mounted a bid to have his case thrown out for being brought out of time.
But Mr Wilson’s barrister, Frank O’Donoghue QC, argued that the alleged policy remained concealed until official papers were released under the 30-year rule.
“The abuse of executive power here is the decision made at central government level to lift a number of members of one faith,” he said.
“If it transpires that the plaintiff’s claim is correct, that it was decided in the face of the internment of a thousand Catholics to intern a healthy number of Protestants and that turned out to be the policy of the British Government ... it’s a very long shot for the Government to come and say the plaintiff should have brought that case in 1974.”
Imprisonment without trial began when soldiers and RUC officers swept into Catholic areas as part of Operation Demetrius in August 1971.
More than 300 people were initially detained in what was then called the Long Kesh prison camp outside Lisburn, Co Antrim.
They were accused of involvement with the IRA.
It would take another 18 months before any loyalists were interned.
Mr Wilson, who is one of a number of Protestants taking legal action against the authorities, claims his subsequent internment was politically motivated.
His arrest was a result of the Government facing criticism for targeting only Catholics, it is claimed.
The court heard that at the time he was involved in political activity. But Mr O’Donogue said the Government wrongly equated that with involvement in terrorism.
His client was never prosecuted for any offence during the internment.
The judge was also told that a consultant psychiatrist has assessed Mr Wilson as having suffered a related injury.
Following submissions Mr Justice O’Hara reserved judgment on the bid to have the claim stopped.