The Fianna Fáil leader Micheál Martin has revealed he has been contacted by another Garda whistleblower.
Mr Martin says he met with him and was handed a dossier about a murder case which the man alleged was not properly dealt with.
He has also confirmed he has been in contact with a female whistleblower in the force who was the subject of newspaper reports at the weekend.
Fianna Fáil says any additional information they get in relation to whistleblowing in the gardaí will be passed on to the Taoiseach Enda Kenny.
Deputy Martin says the man who contacted him was prompted to do so by media reports, but is unable to comment publicly on his experience.
Meanwhile, the Minister for Communiations, Pat Rabbitte, has again said Alan Shatter has his full support as Minister for Justice.
Rabbitte said he expects Shatter will report to Cabinet tomorrow on the controversy involving Garda whistleblower Sergeant Maurice McCabe.