Michael O'Brien, one of the so-called Cardiff Newsagent Three, has demanded an apology for the 11 years he spent behind bars before being cleared and freed by the Court of Appeal.

As three judges rose after giving their reasons for declaring unsafe the 1988 murder convictions of Mr O'Brien, 30, Darren Hall, 31, and Ellis Sherwood, 30, Mr O'Brien exclaimed in court: "Don't we even get an apology after 11 years in prison. It's disgraceful, disgraceful."

Mr O'Brien has now called for a public inquiry into the way South Wales Police investigated the case.

He also claims to have written to the Chief Constable naming the person he says is responsible for the murder.

At the Appeal Court hearing Lord Justice Roch said "shortcomings" in procedures used by police when detaining and interviewing the three at Canton Police Station had played a part in the court's decision to overturn the convictions.

But he stressed: "We are not making any findings of deliberate misconduct against any police officer."

There was also evidence that Mr Hall, whose testimony played a crucial role in the prosecution case at trial, had personality traits which made him prone to giving false evidence.

Had the trial jury known that during the 15-day trial, they "may well have reached different verdicts" said the judge.

The three, then all aged under 21, were jailed for life in July 1988 for the murder of 52-year-old Cardiff newsagent, Philip Saunders, in October the previous year.

Mr Saunders died in hospital five days after being brutally robbed near his home in the city.

Mr Hall gave evidence during the trial that he had acted as look-out while Mr O'Brien and Mr Sherwood beat and robbed Mr Saunders.

Lord Justice Roch, sitting in the Appeal Court with Mr Justice Keene and Mr Justice Astill, gave the court's reasons for its decision late last year to clear and free the three.

He said there had been "clear breaches" of the 1984 Police and Criminal Evidence Act while the three were being detained and interviewed at Canton Police Station after the killing.

Gaps in custody records made it impossible for the court to be sure that admissions had been fairly and properly obtained or that the confessions made by Mr Hall represented the truth.

The court could not be certain that, during substantial periods unaccounted for on the records, "off the record" interviews were not being carried out or that Mr Hall was not having his "ego massaged".

"Nor can this court be sure that admissions were not made by Hall because of the pressure of being interviewed several times whilst being held "incommunicado," said the judge.

"There was evidence of a practice at the time at Canton Police Station of handcuffing persons detained to radiators and other objects.

"We are satisfied that the decision to refuse the appellants access to lawyers was a blanket decision.

"At Canton Police Station, if not elsewhere in the South Wales Police area, it was the practice to withhold access to solicitors until after the police had had the opportunity to interview detainees," he added.

Lord Justice Roch said Mr Hall's evidence, which was later retracted, had played a "central and crucial part" in the trial.

The court had heard expert medical evidence that Mr Hall "showed a very high level of compliance, to an extreme degree found in only about 2% of the population".

All the experts agreed Mr Hall had low self-esteem and a high degree of impulsivity and, although those personality traits did not mean his confessions were necessarily untrue, they made them "potentially unreliable".

And the judge ruled: "We are satisfied that had a jury heard the medical evidence that we have heard and had evidence of the unsatisfactory way in which the interviews at Canton Police Station, and particularly those of Hall, were conducted, a jury would probably have taken a different view of the reliability of Hall's assertions.

"That conclusion, in our judgement, is sufficient to determine these appeals and to lead us to the conclusion that these convictions were unsafe and should be quashed.

"The evidence, both factual and expert, which has been placed before us has satisfied us that this is a case in which such evidence would now be admissable, and that a jury having heard such evidence may well have reached different verdicts."

The judge said: "In reaching these conclusions we are not making any findings of deliberate misconduct against any police officer, nor could we do so, not being a court which makes findings of fact.

"Even were we to be a fact finding court, we could not make any such finding in the absence of hearing any evidence from those detained and interviewed or from the police officers involved in the interviewing process."