Winston Peters was challenged by Simon Bridges in Parliament today over whether or not newly appointed Deputy Police Commissioner Wally Haumaha was once a New Zealand First candidate.

The Acting Prime Minister categorically denied there was a conflict of interest in Mr Haumaha's appointment and said he was never a NZ First candidate when quizzed in Question Time.

"When did he disclose to Jacinda Ardern that Wally Haumaha was once a New Zealand First candidate?" Mr Bridges asked.

Mr Peters was animated in his response to the question.

"The first thing that we don't do is make something up that wasn't true, Mr Haumaha was never a NZ First candidate, the Rotorua Post is not accurate in this matter, plus it doesn't even say that does it Mr Bridges?" Mr Peters said.

The National Party leader then replied by quoting the article referenced by the Acting Prime Minister.

"Does he dispute the Rotorua Post from 2005 when it said last month that Mr Haumaha was announced as NZ First Rotorua candidate but then the party backtracked and said he was 'a representative and not a candidate,'" Mr Bridges said.

The answer from Mr Peters was once again a direct denial.

"Very sadly Mr Bridges that story is not true, we've been through all the 2005 papers he was never announced as a candidate end of story."

Yesterday Cabinet agreed to launch as independent inquiry into Mr Haumaha's appointment to the role of Deputy Police Commissioner over comments he made about the Louise Nicholas rape case.

Ms Nicholas alleged she was raped by police officers as a teenager in the 1980s which resulted in criminal trials. Three were acquitted of rape but one officer was jailed for attempting to obstruct or defeat the course of justice.