A former garda detective inspector has said there was a culture of "squaring", or quashing, minor road traffic offences by gardaí when he was in the force - and it ran from the top down.
It follows calls by four independent TDs for an independent investigation into allegations that 6,000 traffic offences were quashed by senior gardaí in the last four years.
Gerry O'Carroll, now a columnist with the Evening Herald, said quashing offences was common practice when he was a garda, but only where minor offences were concerned.
"There's no point in denying (that) for anyone of my vintage, it was part of our culture," he said.
"Before you'd get to court (as a young garda having made 20 or 30 'detections' of offences), you'd have calls from other members in the station and around the country asking you if you could do something."
The Minister for Justice Alan Shatter said last week he was concerned that politicians and media coverage may prejudice an investigation into the quashing of tens of thousands of penalty points.
Mr Shatter told the Dáil he had received an interim report and there may be nothing inappropriate about the quashing of points.
He said while he is taking the issue seriously, early signals are that in some cases there was nothing untoward with what went on.
Garda Commissioner Martin Callinan confirmed a "vigorous and comprehensive investigation" was underway into the quashing claims.
He said any allegations of impropriety against members of the force was a matter of huge concern to him but he added any wrong doing would be highlighted in Assistant Commissioner John O'Mahoney's internal investigation.