Justice Iarfhlaith O'Neill has asked for more time to investigate the treatment of whistleblowers in the gardaí.

It follows allegations that the Garda Commissioner Noirin O'Sullivan was part of a 'smear campaign' against officers complaining about the force.

Ms O'Sullivan has denied all wrongdoing.

Justice Minister Frances Fitzgerald says she has received a letter from Justice O'Neill, seeking a further extension of time in which to complete his review.

Ms Fitzgerald says Justice O'Neill expects to be in a position to submit his report by December 9th.