Court documents released by Auckland District Court Judge Edwin Paul last week show Ross, Zhang and Colin Zheng face charges of deception over the $100,000 donation in 2017. All four defendants also face charges of deception over a $100,050 donation in 2018. Additionally, Hengjia Zheng is also facing a charge of providing misleading information to the Serious Fraud Office (SFO).

The SFO announced in January that criminal charges would be filed against the four men, at the time unnamed. Their identities were revealed last week, with each releasing statements stating they would defend themselves.

It was initially understood the charges related to a single $100,000 donation from Zhang to National, which was revealed during Ross' public falling out with Bridges in 2018. Ross alleged that the donation had been chopped up into smaller amounts to stop it needing to be declared. But last week it emerged charges also related to a second $100,000 donation.

The court documents show the SFO alleges "the defendants adopted a fraudulent device, trick, or stratagem whereby the 2018 Donation was split into sums of money less than $15,000, and transferred into the bank accounts or eight different people, before being paid to, and retained by, the National Party".

After court on Tuesday, Ross said he had "never been involved in any deceptions to do with donations".

"At the time these donations were made to the National Party, I wasn't aware of any conspiracy to defeat the Electoral Act by anyone. I was the whistleblower. I still consider I was right to raise these concerns.

"There was no own goal here. I have to trust the justice system in this country to establish that, otherwise, who is going to come forward in the future as a whistleblower on important issues like this."

No MPs or board members from the National Party nor Simon Bridges are charged with anything.

The National Party released a statement on Tuesday saying it "has always maintained [it] had nothing to do with alleged illegal activity regarding the donations recently investigated by the Serious Fraud Office".

"The Party does not accept the way Jami-Lee Ross is characterising his part in the donations which have led to charges being made against him, not the Party.

"This has always been about a vendetta by Mr Ross."

It said a trial will involve evidence that wil "inform the public of the true facts".

The Opposition leader said last month he had "no intention of keeping" the $100,000 donation at the centre of the SFO investigation and that he had written to the Electoral Commission to ask what to do with it.

Asked by a reporter on Tuesday last week if he would also return the second $100,000 donation, Bridges replied: "The problem is I don't know anything about it."

Bridges has consistently denied any wrongdoing.

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

The SFO has announced it is also investigating the New Zealand First Foundation over allegations the New Zealand First Party was hiding donations through it.