Gardai are not permitted to double-job for private security firms, and such activity is not widespread, the Garda Commissioner has told an Oireachtas Committee.
Mr Pat Byrne said it was in breach of regulations for serving members of the force to engage in private security work during their spare time.
But calling on anyone with information about such a practice by Garda officers to report it, he added: "I'm not so sure it's a particular problem at this time."
The Commissioner was appearing before the Joint Committee on Justice, Equality, Defence and Women's Issues and responding to questions from the Green Party TD, Mr Dan Boyle.
Mr Boyle had asked if private security "nixers" by gardaí were acceptable, given the "very large-scale conflict of interest".
Mr Byrne replied that in the past a number of gardaí had been cautioned about doing such work, and in one case he had demanded an officer's resignation.
He had no difficulty taking such action, he added, and he urged anyone with evidence of officers doing private security work to come forward.
But he repeated that he did not believe there was a problem in this regard.
Mr Byrne also defended the force's overall performance, despite the 18 per cent rise in "headline" crimes recorded in the Garda's 2001 annual report, published last month.
During an angry exchange with the Fine Gael TD, Mr John Deasy, he pointed out that, until last year's rise, the number of crimes annually had fallen under his commissionership from about 100,000 to 73,000.
Asked by Mr Deasy if this meant he was "comfortable" with the current level of crime, Mr Byrne accused the TD of being facetious.
Describing the Garda Siochána as "a people's police force", the Commissioner welcomed demands for more accountability and better performance, but said it was important that this trend did not demoralise the force.
He identified traffic issues, organised crime, particularly that "emanating from eastern Europe", and the problems posed by an increasingly multicultural Ireland as challenges the force would have to deal with.
In response to a question from the committee chairman, Mr John Ardagh TD (FF), he said gardaí had made a number of "strides" to combat paramilitary involvement in private security work and in extortion of businessmen, and added: "I don't think this will be a problem in the future."
The Commissioner faced strong criticism over the force's inability to solve a series of cases involving missing persons, with Mr John McGuinness TD (FF) saying there was no comparison between Garda inquiries and the approach taken by British police in cases such as the Holly Wells and Jessica Chapman murders.
Mr McGuinness accused the Department of Justice and the Garda of "buck-passing"on the issue and suggested it was time for gardaí to admit their shortcomings and bring in expertise from outside the jurisdiction.
