The defendants are scheduled to appear in the Auckland District Court on February 25.

"I have always maintained I had nothing to do with the donations," Bridges said. "As I have always said the allegations against both myself and the Party were baseless and false."

The SFO launched an investigation in March 2019 into National Party donations after the police referred a complaint by former National MP Jami-Lee Ross.

Ross - now an independent MP - accused Bridges of electoral fraud in October 2018 sparked by his allegation the Opposition leader had asked him to collect a $100,000 donation from a wealthy Chinese businessman.

Ross said the donation arrived in amounts smaller than $15,000 - the threshold at which donations have to be declared by law - and that Bridges had stressed it should not be made public.

Ross released a recorded phone conversation between him and Bridges, where he could be heard asking his then-leader what to do with the $100,000 donation.

University of Otago law professor Andrew Geddis said at the time the alleged offence carries a two-year prison sentence and would "lead to automatic expulsion from Parliament".

Bridges has always denied any wrongdoing.

"This was always just a vendetta by a disgruntled former MP," Bridges said.

Ross raised further allegations against Bridges in April 2019 during a select committee where he implied Bridges was involved in the Chinese community's attempts to have a Chinese minister appointed.