Philip Saunders, murder victim

Mr O'Brien launched a �1.1m claim against the Home Office last month for the 11 years he spent in prison for the murder of Philip Saunders. The Home Office has yet to offer its response.

Issuing the action against South Wales Police at Cardiff's Civil Justice Centre on Monday, Mr O'Brien's solicitor Ms Nogah Ofer said the case was one of the first brought in the UK for "malicious prosecution for murder".

In February this year, the Crown Prosecution Service announced no officers involved in the case would be charged.

South Wales Police then confirmed no action was to be taken against any officers connected with the so-called Cardiff Newsagent Three case.

Mr O'Brien was found guilty of Mr Saunders' murder in Fairwater in 1987 together with Darren Hall and Ellis Sherwood, from Cardiff.

If South Wales Police would admit liability, that's what Michael needs.

Nogah Ofer, solicitor

Having repeatedly protested their innocence and following a lengthy legal campaign, the three men were freed in 1999 when their convictions were overturned by the Court of Appeal amid concerns over the way the investigation was conducted.

During his time in prison, Mr O'Brien's father and daughter both died, and he is now claiming for compensation for the trauma he suffered while in prison and for loss of earnings.

Mr O'Brien said said he wanted the officers who carried out the investigation to be "brought to book" and he is seeking an official apology from South Wales Police.

A force statement said Thames Valley Police had conducted an internal investigation on behalf of the Police Complaints Authority and concluded that no disciplinary action should be taken.

In the statement the force said, as an organisation, it had accepted that "mistakes were made".

Ellis Sherwood: Freed on appeal

Ms Ofer said it was difficult to imagine a "worse abuse of power" than jailing a person for murder they had not committed.

"South Wales Police have a duty to the public to make an example of these officers to stamp out such practises and make sure this never happens again."

She added: "If South Wales Police would admit liability, that's what Michael needs.

"He needs to be able to put his life back together. He has been suffering from very serious post traumatic stress disorder.

"What he wants is acknowledgement, not a huge amount of money."