The Taoiseach has said he is fully confident the Garda will investigate any complaints against members of the force.
He was speaking following last night's Prime Timedocumentary in which claims of physical abuse were made against some gardaí by members of the public.
Speaking before his departure for Germany, Mr Ahern said a complaint he had received from a constituent about the gardaí a couple of years ago had been completely sorted out.
But the Irish Council for Civil Liberties (ICCL) said the Government must move immediately to introduce an independent Garda Ombudsman.
Responding to an allegation by a retired Circuit Court judge that gardaí had lied in his court, the ICCL said the proposed a Garda Inspectorate would not have the required independence because it was part of a Garda Bill.
Retired judge Mr Anthony Murphy told Prime Timethat "there have been occasions when the guards have committed perjury in my court".
Ms Aisling Reidy, ICCL director, said the programme "encapsulates what happens when there is no independent complaints mechanism to monitor and punish abuse by law-enforcement agencies - a culture of denial and impunity emerges, as exists amongst certain elements of the Gardaí.
"It illustrates that as long as we do not have an effective complaints mechanism, there is an ongoing failure to protect basic human rights. With the European Convention on Human Rights recently been given effect in Irish law, it is all the more important that the obligations it imposes on the government . . . are met," she said.
The Labour Party leader, Mr Pat Rabbitte, said the time for "foot-dragging" on the introduction of a Garda Ombudsman must now end. The Minister for Justice must establish an ombudsman's office with powers and resources equivalent to those available to the police ombudsman in Northern Ireland, he said.
Mr Rabbitte said the Prime Timedocumentary had painted "a shocking picture of systematic abuses by members of the gardai".
"There is hardly a member of the Oireachtas who will not have come across of abuse similar to those depicted last night, but the totality of the cases reported in the programme as well as the unprecedented criticism made by a former Circuit Court judge was quite shocking," Mr Rabbitte added.
He said the details in last night's programme did suggest a "serious breakdown of discipline and order within some sections of the force" and it did the Garda no service for senior officers, representative bodies or the minister to "continue burying their heads in the sand and deny the scale of the problem that exists".
The Green Party called for the proposed Garda Ombudsman's office to be completely independent from the Garda Síochána.
The party's justice spokesman, Mr Ciarán Cuffe, said public confidence in the Garda was "at an all-time low".
"It is crucial that Minister McDowell ensures that the proposed Office of the Ombudsman is fully
independently staffed from the outset. The current arrangements whereby the gardai investigate cases presented to the Garda Complaints Board are completely inappropriate."