Fine Gael TD John Deasy has claimed that he was approached in January 2014 by a senior garda who made allegations against garda whistleblower Sergeant Maurice McCabe.
Speaking on RTÉ's Prime Time, the Fine Gael backbencher said the senior garda made very derogatory comments about Sgt McCabe, saying that he was not to be trusted.
He said he later believed that there was a campaign run by gardaí at a senior level against Sgt McCabe.
Mr Deasy said he asked to meet Taoiseach Enda Kenny privately to discuss the campaign against Sgt McCabe.
The Waterford TD said he told the Taoiseach that Sgt McCabe should be listened to and that he would be vindicated, and said the Taoiseach acknowledged his comments.
Mr Deasy said he thinks the campaign against Sgt McCabe was effective.
He said the State needs to do more but he did not want to single out Minister for Justice Frances Fitzgerald as the issues predated her time in the Department of Justice.
Asked about the Taoiseach's record, he said he would find it very hard to defend anyone involved in the Government's handling of the situation.