The NSW corruption watchdog's right to dramatically put surprise evidence to witnesses during public hearings - often resulting in a "gotcha" moment - is set to be the subject of a fresh inquiry into its powers.

The chairman of the parliamentary committee on the Independent Commission Against Corruption, Liberal MP Damien Tudehope, believes an inquiry into whether witnesses should be afforded procedural fairness, as is the case in a criminal court, is "worthwhile".

Damien Tudehope, the chairman of the parliamentary committee on the Independent Commission Against Corruption. Credit:Kate Geraghty

At present ICAC is able to introduce new evidence during a public hearing, upon which witnesses may be questioned, without them or their legal representative having access to it beforehand.

The tactic was the subject of complaints by barristers for witnesses involved in the recent inquiry into Liberal party fundraising before the 2011 state election, including former police minister Mike Gallacher.