THE girlfriend of gangland murderer Brian Rattigan will not face charges after highly confidential personal details of a jury who convicted her boyfriend were found at her apartment, sparking a major criminal investigation.

Twenty-six-year-old Natasha McEnroe, from Drimnagh in Dublin, was arrested last March after the names and addresses of the jurors who found her boyfriend guilty of murder were found in her apartment in Adamstown, west Dublin. However, a source said McEnroe will not be charged in relation to the "worrying discovery".

Under the law, as a defendant, Brian Rattigan was entitled to access to the personal details of the jury in his case. However, this did not mean that Natasha McEnroe was entitled to have this information in her possession.

But as the young woman told gardaí that Rattigan must have left this confidential information at her apartment, there is insufficient evidence to charge her with any criminal offence.

Section 16 of the 1976 Juries Act states: "Every person shall be entitled to reasonable facilities to inspect a panel of jurors free of charge and a party to any proceedings, civil or criminal, to be tried with a jury shall be entitled to a copy free of charge on application to the county registrar."

The book of evidence in John Gilligan's murder trial was also found at McEnroe's home. Detectives are probing why she had this in her possession and a source said it was a "worrying development of possible major significance". Gilligan was found not guilty of the 1996 murder of journalist Veronica Guerin. Rattigan and Gilligan are both housed at Portlaoise prison.

Fine Gael's justice spokes-man Charlie Flanagan said it was a "major anomaly" in the law that allows those on trial to access jurors' personal details and he has raised it with justice minister Dermot Ahern.

In December 2009, Rattigan was sentenced to life in prison for the murder of rival gang member Declan Gavin in August 2001 outside a fast food restaurant. It was the first murder in the so-called Crumlin/Drimnagh feud, which has claimed the lives of 16 people so far.