A long-serving MP is concerned his select committee's work has been undermined, by the government's mishandling of the Mike Sabin saga.

Labour's Phil Goff sits on the law and order committee - which Mr Sabin continued to chair until the end of last month, despite facing a police investigation.

Mr Goff says the conflict of interest should have been clear to Mr Sabin and his government bosses.

"The committee or the principle has certainly been compromised.

"We have the responsibility for running the rule over the police and it's very hard for a person who's chairing that committee to do so if he's currently under investigation by the police as he was at the time."