Fionnan Sheahan said it was a surprise to get "a resignation of this magnitude" and that it was now an "exceptionally serious situation for the government".

He told Pat Kenny "that the upshot of this entire affair is that the level of oversight that the Gardai find themselves subjected to is going to change."

Callinan resigned citing family reasons but Sheahan said even though there were other options available to him "he has chosen to leave his words on the record".