NSW Labor will quarantine $100,000 of donation funds at the heart of a corruption investigation which is asking questions about a sitting Labor MP, former party boss, a billionaire property developer and cash donations linked to a prominent family of restaurateurs.

Key points: ABC can reveal 20 donations totaling $100,000 made on the same day to NSW Labor are target of corruption probe

ABC can reveal 20 donations totaling $100,000 made on the same day to NSW Labor are target of corruption probe Most of the donors are connected to a well-known Sydney restaurateur family

Most of the donors are connected to a well-known Sydney restaurateur family Corruption watchdog examining "straw donor" theory and asking questions about billionaire property developer

The probe by the NSW Independent Commission Against Corruption (ICAC) burst into the public arena in December, when officers raided the NSW ALP headquarters over a fundraising dinner on March 12, 2015.

Bill Shorten, Chris Bowen and a who's who of federal and state Labor politicians attended the dinner, which was just over two weeks before the NSW election.

It was formally organised by Chinese Friends of Labor — an ALP body designed to win votes and solicit donations from NSW's electorally-important Chinese-Australian community.

Since the raid the ALP headquarters has been a hotbed of rumours about what ICAC has been investigating but little was known, until now.

The ABC can reveal the investigators are focusing on 20 donations linked to a Chinese Friends of Labor dinner totalling $100,000 that were lodged on April 9, 2015, by a dozen people and businesses.

Do you know more about this story? Email investigations@abc.net.au

Crucially, ICAC is examining whether the $100,000 was in fact given by so-called "straw donors" — front people who agree to put their names to donations from other people to political parties. That is a crime under NSW electoral law.

The ABC's report today prompted condemnation from Premier Gladys Berejiklian.

State Opposition Leader Michael Daley has asked his party to quarantine $100,000 worth of donations while the corruption watchdog investigates their origin.

"I don't know if there's any tainted money in those donations, but if there is, I don't want a bar of them, and we won't be using any of them in the campaign," Mr Daley said.

Ms Berejiklian says electoral laws in new south wales are the strongest in the nation and the probe is worrying.

"It's now a matter for … the Labor Party and ICAC, but it's at face value very concerning," the Premier said.

Paper trail shows $100,000 in donations on same day

The ABC examined the public donations register and spoke with people involved with knowledge of the investigation.

The donations were all in $5,000 amounts and most if not all were made in cash on the night of the dinner.

Most of the donors gave $10,000 in total — $5,000 to the NSW Labor Party and $5,000 to Country Labor — the ALP's sister party for the bush which has no connection to inner-city Labor supporters.

At the time, NSW electoral law banned individuals from giving more than $5,000 to a political party in a single year; the NSW ALP and Country Labor were considered separate entities at the time.

Opposition leader Bill Shorten, former NSW Labor leader Luke Foley and NSW MLC Ernest Wong were among politicians present at the 2015 dinner. ( Facebook )

Most of the $100,000 in donations centre on long-time Labor supporter Jonathan Yee.

Along with his family he owns the Emperor's Garden restaurant in Sydney's Chinatown, which was founded by his father Stanley in 1979.

At Chinese new year celebrations in Sydney yesterday, Mr Yee was given pride of place, and introduced NSW Opposition Leader Mr Daley to the crowd.

After the introduction Mr Daley shook Mr Yee's hand and told him: "Well thank you very much Jonathan, and thanks for all of your friendship and everything you do."

Mr Yee made a donation, as did his mother and brother. So did the Yee family company which owns the restaurant.

Two of the others donors have worked at Emperor's Garden and a third donor is a company which owns a gift store next door to the restaurant.

In a statement to the ABC Jonathan Yee confirmed he "personally knows" most of the 12 donors who gave money as part of the $100,000 sum given on April 9, 2015.

"I did solicit most of those donors with the exception of two," he said.

Two other donors the ABC spoke to said they could not comment because of the ongoing ICAC investigation.

The Chinese Friends of Labor dinner at The Eight Restaurant in 2015 was attended by hundreds of people. ( Facebook )

Labor hopeful raising cash for political career

Stanley Yee's eldest son, Jonathan, is an aspiring Labor politician who unsuccessfully ran as a party candidate at Sydney City Council's 2016 election.

According to three people close to Jonathan Yee and with knowledge of the donations, there was nothing improper about the donations he solicited.

Those people said the money was a result of Jonathan Yee encouraging people to donate on the night, in an attempt to prove his fundraising abilities to the Labor Party.

"That's how you get endorsed by Labor if you're Chinese[-Australian], you show them you can raise money," one of the three people said.

Emperor's Garden is a popular eatery in Sydney's Chinatown. ( ABC News: David Maguire )

Jonathan Yee was chairman of Chinese Friends of Labor until late 2018 and helped organise the 2015 dinner.

When approached by the ABC Mr Yee said he could not respond to questions about the ICAC probe because he was "part of the investigation".

"Chinese Friends of Labor is a vehicle to promote Labor Policy to the Chinese Community and that the Chinese Community can use the association to convey community issues to the Labor Party," he said, adding Chinese Friends of Labor is registered by NSW Labor and acts in its interests.

"It is also a vehicle to [raise funds] for Labor through dinners like 12th of March 2015."

He was unaware there was a cap on donations in 2015 and he was not informed of such by the ALP, he said.

"If I knew I would have asked [the other donors] just to donate $5,000 rather than $10,000," he said.

Straw donor theory

ICAC appears to be considering whether the donors were fronts for someone else.

Based on conversations with three people involved in the investigation, the ABC has confirmed ICAC is looking into whether the donations were in fact a single cash gift given by another unidentified person and covered up via so-called straw donors.

Straw donors are people who agree to put their name to donations actually made by other people who wish to obscure the source of the money.

That is potentially a crime under NSW election law.

The ABC does not suggest that Jonathan Yee is suspected of being aware of any straw donations which may have been made as part of the 2015 dinner.

The property developer, the politician and the party boss

The ABC has confirmed via a number of sources that three of the people ICAC is asking questions about are: Chinese billionaire property developer and one of Australia's biggest political donors, Huang Xiangmo; NSW Upper House member Ernest Wong; and former NSW ALP general secretary Jamie Clements.

Property developer Huang Xiangmo (second from left) with Ernest Wong (left), former prime minister Julia Gillard and former senator Sam Dastyari in 2013. ( Supplied )

Since 2009 property developers have been banned from making political donations in NSW.

Mr Huang moved to Sydney from the southern Chinese province of Guangdong in 2011.

Since then he has become one of, if not the, most powerful figures among a group of pro-Beijing businesspeople in Australia, though he has always maintained that his donations were legitimate and not designed to influence Australia's political system.

When asked about his relationship with Mr Huang, Jonathan Yee told the ABC: "I have no relationship with Mr Huang and I am aware that the allegations were made about Mr Huang during my interview with [the NSW Electoral Commission]".

The ABC has documented Mr Huang's meteoric rise among Australia's political elite, including how he:

Cultivated relationships with virtually every senior federal and NSW politician from the Coalition and Labor over the last eight years

Cultivated relationships with virtually every senior federal and NSW politician from the Coalition and Labor over the last eight years Witnessed his friend Ernest Wong take the NSW Upper House seat of Eric Roozendaal, who Mr Huang later employed.

Ernest Wong is a member of the New South Wales Legislative Council. ( Supplied )

Mr Wong is a long-time associate of Mr Huang and was the first Australian politician to form a relationship with him.

At the time of the dinner, Mr Wong was Jonathan Yee's political mentor, and for a time Mr Yee was considered to be Mr Wong's heir-apparent in NSW Labor.

Jonathan Yee (third from front right) and Ernest Wong (fifth from front right) in Guangdong in November last year. The picture was published on a Chinese Government website. ( Guangdong Overseas Chinese Affairs Office )

Mr Wong was recently quizzed by ICAC about his political career, his connection to the Yee family, Huang and the 2015 donations, according to people with knowledge of the matter.

Mr Wong was unable to comment on the ICAC investigation, but was "more than happy to cooperate with any [i]nvestigation relating to this matter, if and when he is contacted by the relevant authorities," his spokeswoman said.

Mr Clements was NSW ALP general secretary at the time of the donations.

Jamie Clements resigned from the position of NSW Labor general secretary in 2016. ( AAP: Paul Miller )

He resigned from his role in early 2016 when he was accused of providing electoral roll details to a union associate. He was later found guilty and fined $4,000.

ICAC has also spoken to NSW ALP staff members involved in the 2015 donations, according to people with knowledge of the donations.

The ABC understands that the corruption watchdog began investigating as the result of a formal referral from the NSW Electoral Commission.

If ICAC finds evidence of criminality it has the power to refer the matter to the NSW Director of Public Prosecutions.

If it resulted in charges, it would be the biggest donations scandal since the corruption watchdog's Operation Spicer of 2012-2014, which targeted a scheme by members of the NSW Liberal Party to launder illegal donations.

The ICAC investigation also comes at a bad time for the Labor Party given the NSW and federal elections are expected in the next four months.

The ABC contacted Mr Wong, Mr Huang and Mr Clements. All declined interviews.

Location, location

The ABC has previously reported that when Mr Clements left the ALP he started a legal practice in offices owned by Mr Huang's companies.

Mr Clements currently has an office on the seventh floor of an office block on Pitt Street in Sydney's CBD.

The entire seventh floor is owned by Mr Huang's Yuhu group of companies and also hosts the offices of the most important pro-Beijing lobby group in Australia, the Australian Council for the Promotion of the Peaceful Reunification of China (ACPPRC).

In August last year a new company was registered on the seventh floor of the Pitt Street office block.

Digilink Media Group appears to be a Chinese social media account management firm.

It occupies the same Huang-owned suite as Mr Clement's legal practice. Ernest Wong's sister and Jonathan Yee own 5 per cent each of the new firm.

"I am only a shareholder and I play no part of the companies (sic) day to day business," Jonathan Yee said in his statement.

"I took no part in hiring or decide where to hire an office for the company. I also do not know the details of the lease.

"The company has no link to Jamie Clements but we do share the space with him to my knowledge.

"Digilink is in no way linked to Mr Huang or his company Yuhu Group," he said, adding that the company also had no link to the ACPPRC.

A Labor Party spokesman said NSW Labor was aware of an investigation into historic political donation matters.

"NSW Labor has complied with all applicable laws and regulations relating to political donations," the statement said.