The Irish branch of the NUJ has called on members who have evidence of journalists engaged in corrupt practices to report them to the union's Ethics Council.
The NUJ said it is also seeking a meeting with the Minister for Justice, Equality and Law Reform Michael McDowell to discuss his claim that journalists have been engaged in bribing gardaí.
Mr Séamus Dooley, Irish secretary said that the reputation of the profession has been tarnished by unsubstantiated claims that some journalists are engaged in corrupt practices.
Mr Dooley said: "The NUJ deplores checkbook journalism and does not believe that journalists should buy stories. We have no evidence that journalists are engaged in paying security sources for stories or tip-offs. If any member has such evidence it should be presented to the NUJ for investigation by the Ethics Council.
"The NUJ Code of Conduct clearly states that journalists have a duty to maintain the highest professional and ethical standards."