The Government has published the report by Sean Guerin SC into allegations of garda misconduct.
In his report, Mr Guerin recommended a comprehensive" Commission of Investigation be established to investigate the issues that "remain unresolved" arising from complaints made by whistleblower Sergeant Maurice McCabe.
"There is cause for concern as to the adequacy of the investigations that have taken place ... and as to whether all appropriate steps have been taken," he said in his conclusion.
"No complex organization can expect to succeed in its task if it cannot find the means of heeding the voice of a member whose immediate superiors hold him in ... high regard."
"Ultimately, An Garda Síochána does not seem to have been able to do that.
"Nor does the Minister for Justice [Alan Shatter], despite his having an independent supervisory and investigative function with specific statutory powers."
The 'Review of the Action Taken by An Garda Síochána Pertaining to Certain Allegations Made by Sergeant Maurice McCabe' can be read here.