Top cop Wally Haumaha was once closely associated with the New Zealand First party, which the National Party claims raises serious conflict of interest questions over an inquiry into his promotion.
Acting Prime Minister and New Zealand First leader Winston Peters announced an inquiry into the process which led to Haumaha's appointment as the new deputy commissioner, following a Herald investigation which revealed Louise Nicholas' anger at his promotion.
Haumaha was friends with the men she accused of raping her and continued to support them after the scandal broke.
Her allegations - including being violated with a police baton - triggered an exhaustive police investigation, Operation Austin, as well as a Commission of Inquiry into the culture of the police and how sexual assault cases were investigated.
One officer told the 2004 Operation Austin investigation into the police sex allegations that Haumaha - who was appointed to the senior role in May - described Nicholas' allegations as "a nonsense" and that "nothing really happened".
Haumaha was appointed on the recommendation of Nash following a State Services Commission recruitment process in which Police Commissioner Mike Bush sat on the panel.
Peters later announced an inquiry, the terms of which will be announced after a Cabinet meeting today.
On Friday, Peters deflected a question about Haumaha having been selected as the New Zealand First candidate for Rotorua in 2005.
"There are hundreds of people who have stood for New Zealand First; probably hundreds more will in the future," the acting Prime Minister said.
"He was not a candidate for New Zealand First and that's the end of it."
Archives of the Rotorua Daily Post newspaper on August 19, 2005 show Haumaha was announced as the party's candidate at a community event.
Just four days later, the paper reported Fletcher Tabuteau - now the party's deputy leader - would be the New Zealand First candidate for Rotorua.
The candidate confusion was explained by the party's Rotorua chairman Charles Sturt as Haumaha acting as the New Zealand First "representative" at the meet-the-candidates event.
The next month, September 2005, suppression was lifted when Haumaha appeared in the Rotorua District Court to support his wife who admitted stealing nearly $24,000 from her employer.
The court heard she gambled away the money set aside for her husband's planned 2005 political campaign.
When Haumaha told his wife he had been asked to run as NZ First's Rotorua candidate, she panicked because she had blown the campaign funds, according to the Rotorua Daily Post.
To cover up the missing money and her gambling, she stole money from the bank where she worked to repay the missing funds.
While his political aspirations ended, Haumaha's kept rising through the ranks until his promotion to deputy commissioner.
Through a spokeswoman, Stuart Nash said no one from New Zealand First lobbied him to appoint Haumaha to the senior role.
But ahead of the announcement of the scope for the inquiry into Haumaha's promotion, National Party leader Simon Bridges said there were "serious questions of probity".
"Winston Peters needs to make clear whether he disclosed this conflict of interest at Cabinet given Wally Haumaha was once a candidate, or 'representative', of his party."
The Herald has sought comment from the Acting Prime Minister's office.