Statements made by two former paratroopers accused of murdering an Official IRA leader in 1972 have been excluded as evidence in their trial.
The court heard that the prosecution accepted that if the evidence was excluded the charges against the defendants must fail.
The prosecution is considering an appeal against the ruling, which will be heard on Tuesday at 2pm.
Joe McCann, 24, was shot dead as he ran away from the police and Army on Joy Street in Belfast in April 1972.
Speaking outside Laganside Court in Belfast afterwards, solicitor for the McCann family Niall Murphy said they had “very strongly held views” about the ruling.
He added: “They are mindful that the matter is live before the court and looking forward to the exhaustion of an appeal.
“To that end, we will reserve comment until next Tuesday.
“They very much look forward to an appeal being launched.
“That’s under consideration at present.
“We will know the position more clearly on Tuesday morning.
“There are very strongly held opinions in respect of what has transpired in this case.
“We will make those public at the appropriate time.”
The court heard that the only evidence implicating the defendants, soldiers A and C, came from two sources.
The first was statements they made to the Royal Military Police in 1972, the second source was statements and answers which they volunteered to the Historical Enquiries Team (HET) of the PSNI in March 2010.
The defence team argued that all of the evidence was inadmissible and should be excluded under Article 74 and 76 of the Police and Criminal Evidence Northern Ireland Order 1989.
Article 74 states that a confession that may have been obtained by oppression of the person who made it should be inadmissible.
Article 76 allows for the exclusion of evidence if its admission would have an adverse effect on the fairness of proceedings.
Mr Justice O’Hara said the prosecution had accepted that if the evidence was excluded the charges against soldiers A and C must fail.
He said the decision was therefore “fundamental” to the trial proceeding any further.
The prosecution accepted that the 1972 statements were not admissible on a number of grounds, including that the soldiers were ordered to make them, they were not conducted under caution, there was no access to legal representation and the Army policy of not asking soldiers to provide an explanation or rationale for their actions.
However, they argued that those statements became admissible because they were adopted by the defendants at their interviews in March 2010.
However, in his ruling, Mr Justice O’Hara said the outcome of the Article 76 judgment was effectively “inevitable”.
He said: “What was required in this case, and what never took place was that the PSNI should have interviewed the defendant under specific caution to suspect a crime of murder.
“If that had been done, and if admissions had been made, then prosecutions would have been possible.”
He said it was not legitimate to put the 1972 evidence before the court “dressed up and freshened up with a new 2010 cover”.
He said both strands of Article 74 applied, that there was oppression of the defendants in 1972, and that the statements may have been obtained as consequence of things said and done that would likely render any confession unreliable.
He said the prosecution had come “nowhere near” proving beyond a reasonable doubt that the statements were not so obtained.
Additionally, the judge ruled that under Article 76, all the evidence was inadmissible because the manner in which it was obtained would have an adverse effect on the fairness of the proceedings.
He said it could not be allowed that the statements made in 1972, under military orders, be admitted as evidence.
The judge said the exclusion of the evidence was not in any way due to fault on the part of the Historical Enquiries Team.
He also criticised the historical agreement between the RUC and the army, which lasted until 1973, which prevented police from questioning soldiers.
“Many judges before me have condemned that practice.
“I join in that condemnation.”
Prosecution barrister Louis Mably said they wished to consider whether to appeal the ruling.
The defence raised no objections.
The court was adjourned until 2pm on Tuesday.
Video report by Matt Sterling: