Senior members of the Cambodian regime have amassed multi-million-dollar properties and business portfolios in Melbourne, raising questions about the clout of the foreign ruling party in Australia amid its escalating global campaign to silence dissenters.

Key points: Hun Sen's son-in-law owns a seven-bedroom home in Point Cook worth about $1.5 million

Hun Sen's son-in-law owns a seven-bedroom home in Point Cook worth about $1.5 million His company sold a Dandenong South warehouse for $5.08 million in May

His company sold a Dandenong South warehouse for $5.08 million in May The wife of Hun Sen's nephew is the owner of a Berwick house worth about $1.3 million

Community leaders have told the ABC that expat critics of Cambodian Prime Minister Hun Sen are being increasingly subjected to death threats by Cambodian People's Party (CPP) operatives in Australia.

"I've been here for 22 years and we haven't seen such activity [in the past or intimidation at] this level here in Melbourne," lawyer and community advocate Heang Tak said.

Some community leaders believe that those responsible for these activities in Australia are emboldened by the presence of senior CPP members in the country.

There are also questions about whether property purchases by members of the CPP elite have been subjected to the level of scrutiny required by Australia's money laundering guidelines for so-called "politically exposed persons" or PEPs.

Those AUSTRAC — Australian Transaction Reports and Analysis Centre — guidelines acknowledge that people with ties to a foreign government and their families are "in positions that potentially can be abused for money laundering and related offences, including corruption and bribery".

'Hun Sen's favourite nephew': CPP members' millions

The ABC has used property and company records, as well as a research paper which collated data from Cambodia's company registry, to build a picture of the Australian assets of CPP party members.

One of those senior CPP members is Dy Vichea, a Cambodian police chief who also heads the Interior Ministry's central security department.

Mr Dy, 37, who is married to Hun Mana — Hun Sen's eldest daughter — has owned businesses in Melbourne since at least 2002, company records show.

Dy Vichea and his wife Hun Mana at an event. ( Facebook: Hun Mana )

Mr Dy was appointed to his current government role earlier this year, which gives him oversight for investigating money laundering as well as looking into political rivals of the CPP, among other responsibilities.

Property records show he owns a seven-bedroom home in Point Cook worth about $1.5 million, while back in May, his company sold a Dandenong South warehouse for $5.08 million.

He bought the land to build the warehouse for $1.3 million back in 2011, and the warehouse was occupied by his motorbike business, Atomik.

Dy Vichea used this Dandenong South warehouse for his motorbike business, before selling the property for over $5 million in May. ( ABC News: Simon Winter )

The worth of Atomik, which is now housed in another Dandenong South warehouse rented by the business for about $122,000 a year, is unclear.

An automotive business analyst, who wished to stay anonymous, said that $2 million would be a conservative estimate given the rent Atomik was paying, the sale of the previous warehouse, and its manufacturing capacity.

Mr Dy did not respond to requests for comment.

According to a 2016 census, more than 20 per cent of all Cambodian-born people in Australia live in Greater Dandenong, in Melbourne's outer south-east.

Cambodian community leaders say these suburbs including Keysborough and Springvale are also the Australian heartland of the CPP.

Just east of the Atomik factory sits more property owned by another family member of Prime Minister Hun Sen.

Thai Jackie Thi Tien is married to Hun Sen's nephew — Ms Thai is the registered owner of a house worth about $1.3 million in Berwick where her husband, Hun To, is believed to live when he is in Australia.

Hun To, the nephew of Hun Sen, lives in a property worth about $1.5 million in Berwick. ( ABC News: Simon Winter )

Ms Thai also owned a property worth about $650,000 nearby, which she recently transferred to her sister.

Hun To is said to be the most feared of dictator Hun Sen's family members in Australia, according to Greater Dandenong councillor and preselected Labor candidate for the seat of Clarinda, Heang Tak.

Hun To poses during a trip to London earlier this year. ( Facebook: Hun To )

"Hun To is Hun Sen's favourite nephew," Mr Tak told the ABC.

"He has full protection from his uncle. That's what makes people scared of him."

Earlier this year, Hun To confirmed that he'd been questioned by police over death threats to dissidents in Melbourne, but denied any involvement.

Prime Minister Hun Sen's nephew Hun To with one of his sports cars. ( Facebook: Hun To )

He has no official role within the CPP, but, along with his wife, is considered to represent a key part of Hun Sen's empire by community figures, non-government organisations, and experts on the regime.

Hun To is known to travel regularly between Melbourne and Cambodia.

During a visit by the ABC, Hun To's house was vacant, but a relative that was approached at another nearby property said he would tell Hun To the ABC had visited and wished to speak with him.

Only days later having heard nothing back, Hun To was spotted at a temple in Springvale.

As of this year, Hun Sen's son-in-law, Dy Vichea, nephew Hun To and his wife, Thai Jackie Thi Tien, had combined assets in Melbourne worth at least $10 million.

'Not from corruption': financial ties beyond Hun Sen relatives

Kong Vibol taking a selfie with Hun Sen (R). ( Facebook: Kong Vibol )

Although not related to Hun Sen, Kong Vibol is the most senior CPP figure with property interests in Australia.

He returned to Cambodia in 1993 after studying in Australia, and, two decades later, was promoted to head the Cambodian tax department.

But he maintained an eye on Australia, and particularly on a block of land in Keysborough.

The entrance to 212 acres of paddocks at 64 Hutton Road Keysborough. Vibol Kong had a share in a trust that bought the property for $21.4 million in March 2007.

Mr Kong had a share in a trust that bought the property for $21.4 million in March 2007.

His lawyer, Mario Merlo, said Mr Kong no longer had an interest in the land, and made no profit from his share. However the ABC has learned that he maintains links to a number of other properties throughout Melbourne's south-east, as well as a $600,000 Noble Park house which he listed as his Australian address with the Australian Securities and Investments Commission (ASIC).

Mr Kong's mother, sister, and nephews all live in Australia. Mr Merlo maintained that properties linked to his relatives were purchased legitimately, and, in some cases, had nothing to do with Mr Kong.

Mr Merlo, who also represents other members of Mr Kong's family, added that Mr Kong had legitimate business interests that had nothing to do with the CPP or Cambodia.

"It's not from corruption or anything like that," he told the ABC.

Mr Kong and other successful members of the Cambodian community had often come to Australia with nothing and should be celebrated, rather than questioned, Mr Merlo said.

"He's a smart guy who has worked hard … he started with zero," he said.

"As a friend, I find it offensive to him. And it's being done for political purposes."

Personal wealth dwarfs paltry government salaries

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 45 minutes 20 seconds 45 m Champagne With Dictators

Senior CPP members have been able to build their vast personal wealth in Australia, despite being officially paid paltry government salaries of about $1,000 a month back home.

According to an analysis of the Cambodian business register performed by anti-corruption NGO Global Witness, some of those with ties to Australia have far greater holdings back in Cambodia: Mr Dy and his wife Hun Mana have a combined interest in more than $US66 million ($93 million); and Hun To and Thai Jackie Thi Tien more than $US7 million ($10 million).

But Mr Merlo defended the assets to the ABC saying that it was simplistic to question a person's wealth based on their government salary.

Mr Kong and Mr Dy have both been directors of Australian companies and used Australian residential addresses on ASIC records.

In Mr Dy's case, the $1.5 million Point Cook address is still his registered address.

However, both men are senior Cambodian government officials who predominantly live and work in Cambodia.

The revelations raise serious questions about the ability of senior figures associated with the Hun Sen regime to own assets and do business in Australia.

Mr Dy has banked with ANZ since at least 2011, and Ms Thai with Westpac since at least 2012.

Mr Kong's business dealings are more opaque, and it is unclear if he has any accounts with Australian banks.

Under money laundering regulations, Mr Kong, Mr Dy, and Hun To along with their families should have been flagged as politically exposed persons (PEPs) when dealing with Australian banks — if not because of their own roles within the CPP, then because of their relationship to Hun Sun.

"Family members and close associates of PEPs should be treated as PEPs because of the potential that the relationship could be misused," AUSTRAC guidelines state.

Those treated as PEPs must come under greater scrutiny by banks, which then inform AUSTRAC if further suspicions are raised about the legitimacy of their finances.

Sorry, this video has expired Four Corners' Sophie McNeill confronts Cambodian Prime Minister Hun Sen at a rally.

That, in turn, can then lead to further investigations from federal agencies such as the Australian Federal Police (AFP).

It is understood the AFP has no current investigations that relate to property or business interests of CPP figures in Australia.

But money laundering expert Mark Zirnsak said that he was so concerned about general compliance with PEP regulations that he had urged it to be part of the scope of the ongoing Royal Commission.

He added that the questions for Australian banks in dealing with the CPP were two-fold: firstly, were PEP regulations followed, and secondly, if they were, were the transactions cleared by the banks or AUSTRAC?

A spokesperson for AUSTRAC said it did not comment on specific cases but was "aware of allegations regarding unexplained wealth, company links, and property purchases in Australia by a number of Cambodian officials and associates".

Westpac and ANZ declined to comment on whether they treated the CPP figures as PEPs.

'Get f*****': portfolios grow in tandem with rising threats

Cambodian community members say the property portfolios of CPP elite are expanding amid increasing threats to those who criticise Hun Sen's regime.

They say sanctions would help them feel safer when speaking out against or protesting the regime.

Sameth Sao was threatened after he was overheard criticising the regime to his grandmother while they shopped in Springvale. ( ABC News: Simon Winter )

Community member Sameth Sao said he was threatened two years ago by a powerful supporter of the CPP after he was overheard criticising the regime to his grandmother while they shopped in Springvale.

"He said 'get f*****' to me. 'You have to flee'."

Korb Sao, another community member with no relation to Mr Sameth, started speaking out against the regime after villagers from his home of Chikreng in Siem Reap were caught up in a land dispute with the CPP.

Like others who have attended protests against the regime in Australia, he said he's been warned not to return to Cambodia.

"If go to Cambodia I will be in jail or I will die … I know it," he said.

Korb Sao says he cannot return to Cambodia after speaking out against the regime. ( ABC News: Simon Winter )

How will Australia respond? Will it follow the US?

The revelations add weight to calls for the Australian Government to follow the US Government and sanction the CPP, which has been described as running a mafia state.

In June this year, the US Government responded to the increasing violence of the regime in Cambodia and abroad by passing laws which could result in senior CPP members being banned from entering the country, and having their US assets frozen.

Ed Royce, the chairman of the US Government's House Committee on Foreign Affairs, said sanctions were warranted because of the role of senior CPP members in human rights abuses and undermining democracy.

The US Government, anti-corruption NGO Global Witness, and Cambodian community leaders based in Melbourne maintain that the political and business arms of the regime are inseparable.

Former foreign minister Julie Bishop and CPP organiser Sara Nary — also known as Jason — on the far right. ( Facebook: Philip Tan )

Over the course of several calls and exchanges, the Department of Foreign Affairs (DFAT) refused to provide comment on whether they would push for sanctions.

When asked by the ABC to clarify their stance, they said there would be no further comment in the last interaction.

Earlier this year, Monovithya Kem, the daughter of Cambodia's jailed opposition leader Kem Sokha, met with former foreign minister Julie Bishop to ask Canberra to follow Washington, but the meeting yielded no results and no comment was given by Ms Bishop.

But Australian Cambodian community leaders maintain that sanctions would not only signal that Australia rejected the regime and its human rights abuses, but could also discourage the party from striking out against its critics.

Although there is nothing to suggest senior CPP figures with deep ties to Melbourne are personally involved in party activities in Australia, Global Witness also maintains that sanctions protect opponents of the regime.

Global Witness campaigner Emma Burnett said in April that one of the most effective ways for foreign governments to intervene and protect Cambodians was "by preventing Cambodia's corrupt elite from stashing, spending, or growing their ill-gotten gains overseas".

If the push from Global Witness, community members, and federal MPs — including Julian Hill, whose electorate includes parts of Melbourne's south-east — for US-style sanctions to be implemented in Australia is successful, the banks and PEP regulations could effectively be sidelined as investment in Australia would be barred.

Hun Sen's son in the sanction crosshairs as authorities linger

Hun Sen's son Hun Manet speaking at a dinner in October 2016. ( Facebook: Cambodian Sydney Youth )

Cambodian community leader and lawyer, Sawathey Ek, said Hun Manet should be one of the first people hit with sanctions.

Hun Manet is Hun Sen's son and is in charge of ramping up party support among overseas youth, as well as overseeing new "working groups" — seen by observers as recruitment arms for political youth — in the United States, Europe, Canada, and New Zealand.

A Four-Star Lieutenant-General and a Deputy Commander of Hun Sen's bodyguard unit, Hun Manet has visited Sydney, Melbourne, Adelaide, and Brisbane, typically addressing functions attended by hundreds of party faithfuls.

When the US sanctions bill was passed, Mr Royce maintained that Hun Manet should be among the CPP figures specifically targeted.

Sorry, this video has expired Hun Manet filmed recruiting for the party in Sydney (excerpt from Four Corners episode, Champagne with Dictators)

It is understood Hun Manet was recommended because the CPP engaged in similar youth outreach programs in the US as it has here in Australia.

Those US programs were focused on areas such as Long Beach California, which, like Melbourne, has a large Cambodian community.

In June, Labor MP Mark Butler told Parliament that members of his electorate believed the local Cambodian Cultural Association — the sort of organisation that is ultimately controlled by Hun Manet — was a front for the CPP.

He also added that when Hun Manet visited Adelaide, he was hosted by relatives of Hun Sen who live in the north of the city.

"The Cambodian community in Adelaide have expressed to me their fear of the infiltration of CPP operatives and Hun Sen allies here in Australia," he said.

"Australians should feel safe, secure, and free from intimidation, not still living under the thumb of a dictator."

Cambodian Prime Minister Hun Sen in 2016. ( Supplied: The Phnom Penh Post )

The Foreign Influence Transparency Scheme passed Parliament in June this year in response to concerns China was meddling in Australian politics. Under that act, any person or entity undertaking activities on behalf of a foreign principal for the purpose of political or governmental influence must register and comply with the act, and the AFP would then be in charge of investigating alleged breaches of the laws targeting covert, deceptive, or threatening actions by foreign actors.

A spokesperson for the Attorney-General would not comment on whether CPP committees and youth organisations would be required to register to the scheme.

The Cambodian Government has been contacted for comment about sanctions and Hun Manet, but no response was given at the time of writing.