In 2007 the Garda Commissioner directed a review of the case by the Garda Serious Crime Review Team. Over 200 recommendations were made relating to the cases.

This review led to “serious failings” being found as well as “the shortcomings in the management” of the earlier Garda investigation.

These failures, listed by Martin in the Dáil, are: failure to keep a map made of the crime scene, a failure to keep a motorbike helmet found near the crime scene and linked to the crime, a failure to keep custody of material exhibits, including various fingerprints, samples and debris gathered during the investigation.

The taoiseach also said there was a failure to document some potentially important aspects of the original investigation, including whether Brian’s colleagues at Portlaoise Prison were interviewed and whether prisoners at the prison were interviewed.

There was also a failure to interview the Stack family and to interview Brian’s wider group of friends.

“It is plainly and utterly unacceptable that material that was potentially of evidential value to the investigation can no longer be located by An Garda Síochána.

“It is admitted by An Garda Síochána that these are serious matters that had an impact on the investigation,” Martin said.

He formally apologised to the Stack family for these failings.