And Labour leader Pat Rabbitte called the encounter between private investigator Billy Flynn and the minister a "bizarre interlude".

"Unless the minister can make a convincing statement, it looks like he was digging the dirt on Nora Owen, " he said.

McDowell travelled to Flynn's remote house in Enfield, Co Meath, on 10 June last year . . . just days before a crucial Dail debate on the findings of the Morris tribunal. He obtained a large volume of documents concerning representations which Flynn . . . widely regarded as the person whose information helped uncover the scandal . . . had made to Owen.

Days after the meeting, McDowell produced one of the documents on RTE's Questions and Answers. This document was a letter Flynn had written to Owen, when she was justice minister, on 11 March 1997. McDowell's claim was that Owen had ignored all representations and did nothing.

A few days later, McDowell apologised to Owen in the Dail for any inference that she had been remiss in her handling of the letters.

Owen this weekend told the Sunday Tribune: "It's very unusual for a minister to call to the private home of a private investigator while a statutory tribunal is going on. There was no need to call to Mr Flynn.

"Every bit of documentation Billy Flynn sent into the department during my time and after, was available to the minister. I find it extraordinary. It was unnecessary and under the circumstances inappropriate."

Rabbitte said: "It is troubling conduct for a Minister for Justice to take part in. As a senior counsel, Minister McDowell would have known the implications of meeting Billy Flynn where he was a witness at the Morris tribunal and Michael McDowell is Minister for Justice."