The Serious Fraud Office has charged six people in relation to a donation made to the Labour Party.

The Serious Fraud Office (SFO) said on Thursday the defendants are entitled to seek name suppression therefore haven't been named until any name suppression issues have been resolved.

"We note, however, that none of the defendants are sitting MPs or are current or former officials of the Labour Party," the SFO said in a press release.

Labour's general-secretary Rob Salmond said the party followed the law.

"The SFO has announced today that no sitting MPs and no current or former Labour Party officials have been charged in relation to their recent investigation," he said.

"Labour has not sought any suppression orders from the courts. As the matter is before the Courts, we won't be making any further comment."

The SFO launched an investigation in July last year into donations made to Labour in 2017. The SFO is a law enforcement agency tasked with investigating fraud and corruption. 

When the SFO launched the probe last year, Labour Party president Claire Szabo said: "We have not been advised of the specifics of the inquiry, however the Labour Party will fully cooperate with any SFO investigations."

Then-SFO Minister Stuart Nash said at the time: "I had no indication whatsoever that anyone was looking to investigate us, so I don't know who has lodged a complaint with us but, you know, time will tell."

READ MORE

• Māori Party undeclared donations: Electoral Commission notified as soon as error was noticed
• Woman accused of embezzling funds from Defence Force social club accounts
• Church struck off Charities Register after massive fraud uncovered

The SFO has remained tight-lipped on the details of its probe.

Last month police referred the Māori Party to the SFO after it failed to declare hundreds of thousands of dollars in donations on time.

All political donations above $30,000 must be declared to the Electoral Commission within 10 working days, but the Māori Party failed to do so with three large donations made between March and October.

The Electoral Commission revealed earlier this month a second referral to police from another party - a candidate who allegedly failed to disclose donations.

It wouldn't disclose who it was - but he did it himself in a Facebook video: Billy Te Kahika, who co-led Advance NZ.

Police confirmed to Newshub that matter was still being assessed.

The National Party got off with a warning from the Electoral Commission, after it failed to declare $35,000 in donations from businessman Garth Barfoot on time.

But another SFO prosecution, involving donations to the National Party, is set to go to trial in September.

Former National MP Jami-Lee Ross and a trio of businessmen were charged in January last year over donations of $100,000 in 2017 and $100,050 in 2018.

Ross and the other businessmen have pleaded not guilty.