Members of Dean Lyons’s family say they want to know how details of two murders which he did not commit and which could only have been known to the killer ended up in his statement to gardaí.

They say they were interviewed by the Commission of Investigation into the case but have not seen a copy of the report which has been sent to the Minister for Justice and is due to be published next month.

It is understood to have found that a number of gardaí who interviewed Dean Lyons had doubts about his admission that he killed Sylvia Shields and Mary Callinan in 1997. However, senior officers ignored these concerns.

The Department of Justice says it is carrying out an inquiry into how details of the report appeared in a newspaper and may ask the gardaí to investigate.

It is an offence for anyone who receives a draft of the report or part of it to disclose its contents. The offence is punishable by a fine of up to €300,000 and up to five years in jail.

The family of Dean Lyons said today they are still waiting to find out what the Commission of Investigation into the case has concluded.

On 6 March 1997, two psychiatric patients, Ms Shields and Ms Callinan, were murdered in their sheltered accommodation house in Grangegorman in Co Dublin.

Dean Lyons was arrested and was charged after he admitted the murders on and off camera and to his family and legal team.

However, four months later Mark Nash - the now convicted double murderer - confessed to the killings. He later retracted but it subsequently emerged that Dean Lyons was innocent.

Senior Counsel George Bermingham was appointed to find out how Mr Lyons was accused of a murder he did not commit.