National would rename the Serious Fraud Office (SFO) and double its funding to focus on corruption, if elected.
The SFO's funding would increase from $12.7 million a year to $25m a year, and be renamed to the "Serious Fraud and Anti-corruption Agency", under the party's policy announced by leader Judith Collins this morning.
In a statement, Collins said the office's powers - including the ability to compel witnesses and suspects to answer questions put to them without the right to silence - were not being given enough opportunity to be used.
"The SFO takes very few prosecutions, not because there isn't fraud, bribery and corruption in New Zealand, but because the office doesn't have the resources to do its job properly," she said.
"The office needs more investigators and more resources to work with its domestic and international counterparts."
The party's policy document noted the SFO has a 100 percent conviction rate, but takes very few prosecutions - just seven in the 2019/20 financial year.
It quoted the SFO's 2019 annual report, saying its limited resources limited its focus to cases that could significantly impact sections of the economy or the public.
Collins said the name change was needed because New Zealanders needed to better understand the types of crime it is responsible for fighting.
"We want people to know the office's mandate and focus goes well beyond the world of investment, accounting and banking. It also tackles fraud, bribery and corruption in local government, community entities and iwi trusts. It prosecutes wrongdoing in infrastructure contracting, project tendering and central Government, including ministries, Crown agencies and political parties."
Collins acknowledged New Zealand is regarded as one of the least corrupt countries in the world, but rankings were based largely on perceptions.
"In New Zealand's case this is in part because of the relatively small number of proven cases of serious fraud, bribery and corruption we uncover."
The SFO has four investigations into electoral funding - in the Labour Party, by the New Zealand First Foundation, and the Auckland and Christchurch councils, and has brought a case involving the National Party to court.
'A little history there' - Ardern
Labour leader Jacinda Ardern said the Labour-led government had already increased SFO funding by 25 percent.
"We saw the need to support them and that's why we already increased their funding and provided extra targeted funding in recent budgets too."
She said it was "interesting" to hear National now wanted to see an increase in support for the SFO.
"There's obviously a little history there with the opposition leader ... as a previous minister [Collins'] engagement with the SFO led to her job loss".
Collins was cleared of any wrongdoing by an inquiry after she was accused in the 2014 book Dirty Politics of leaking information to her friend and right-wing blogger Cameron Slater.
A separate 2011 email from Slater that was leaked to media during the 2014 campaign had said Collins was "gunning for" Adam Feeley - the Director of the Serious Fraud Office (SFO).
She stood down as an MP in 2014 because she believed her presence in Parliament and as the minister responsible for the SFO was distracting from the party's election campaign.
The inquiry concluded there was insufficient evidence to back the accusation up, and Collins was reinstated in John Key's government in 2015.
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