Former Liberal Democrats legal affairs spokesman Alex Carlile has called for a review of the legal system following the release of the so-called Cardiff Newsagent Three.

Lord Carlile, a QC, said there was a problem with quality of police investigation in major cases and the way evidence was examined.

His comments came after murder convictions against Michael O'Brien, Darren Hall and Ellis Sherwood were quashed by the Court of Appeal.

The three were jailed for life more than 11 years ago for murdering newsagent Philip Saunders in Cardiff.

Speaking to BBC Radio Wales Mr Carlile said the police should use video and other advances in technology as part of their investigation.

He said: "I think we have surely reached the time where so much technology is available that no confession or seriously adverse statment should be accepted without independent confirmatory evidence.

"That is the system they have used in Scotland.

Police questioning

"Great emphasis is placed on positive forensic science evidence perhaps more should be placed on negative findings, when there is no forensic science evidence.

"The way is presented needs to be examined with independence and rigour."

Lord Carlile also said the way police question suspects needed to be overhauled.

"It may be a matter not so much of the individual officers' attitude to offences but the way in which they are trained in their attitude," he said.

"Interviews of suspects are often carried out by only pretty junior officers without real senior supervision and the desire of the junior officer to prodice a result may cloud their judgement.

Public inquiry

"The style of interview may be more aggressive than on paper.

"It really is time for us to have video recorded interviews, the technology is available to us now."

Michael O'Brien. who was cleared of murdering Mr Saunders is now calling for a public inquiry into the case and other investigations carried out by South Wales Police.

"I want a totally independent review of the South Wales Police force's handling of our case and all the other miscarriages of justice," he said.

"They (South Wales Police) don't seem to learn from their mistakes."

The "Cardiff Newsagent Three" were released on bail last year after their case was taken up by the BBC Wales current affairs TV programme "Week In Week Out".

Mr O'Brien is taking part in a candlelight vigil in Newport for John Roden who is currently serving a life sentence for murder.

His family are fighting to clear his name.