Cross the land border from Thailand into Cambodia and what strikes you first are the casinos.

Stretching almost to the security perimeter, they make an incongruous sight: candy-egg coloured concrete boxes, built to service an overseas clientele.

Many others have popped up along the southern border crossing with Vietnam and in urban centres across the country. Some are flash, but many are non-descript, built purely for purpose.

The entrance to one, in the coastal resort town of Sihanoukville, looks more like a large shopping centre than a gambling den.

By one reading, the casinos are a sign of economic renewal in the tiny South-East Asian nation, which has struggled to break free of the deadly legacy of Pol Pot and the Killing Fields.

But their proliferation is stirring up local concerns that the country's development has taken a worrying turn.

In the past two years, Cambodia's growth has become super-powered, fuelled by a dramatic increase in investment capital, which has doubled from $US3.6 billion in 2016 to $US6.3 billion last year.

The border crossing in the Cambodian town of Poipet, on the border with Thailand. ( ABC RN: Antony Funnell )

Around $US5.3 billion of that money came from Chinese interests, according to comments from the deputy secretary of the Cambodian Investment Board.

Locals complain about dodgy land deals favouring Chinese companies and unexpected or forced acquisitions.

"They have money and they buy up everything" is a familiar refrain when talking with ordinary Cambodians.

A growing Chinese interest

Strolling along the beach at Sihanoukville recently, I was forced to navigate through a minefield of rubbish: abandoned wooden kiosks, broken furniture and discarded food and drink utensils.

Behind the refuse lay a newly-erected green construction fence, and beyond that, a scene of demolition.

Late last year, local traders were abruptly forced to shut-up shop to make way for a new Chinese-funded high-rise development.

One restaurateur is now forced to serve meals from the garage of his house, tucked away in a winding back street. The downstairs area of his modest, elevated dwelling is crammed with fridges, freezers and commercial cooking equipment.

Construction in the town of Sihanoukville, in Cambodia. ( ABC RN: Antony Funnell )

In January, growing animosity toward the influx of Chinese money and influence saw the local provincial governor appeal directly to Phnom Penh.

Governor Yun Min sent the Interior Minister a three-page report which, among other things, listed local grievances over the behaviour and influence of Chinese interests in the resort town.

The move prompted a rare acknowledgement from the Chinese Embassy that "a small amount of low-educated [Chinese] people" had been breaking the law in Cambodia.

China's Ambassador, Xiong Bo, rejected any suggestion that the rapid growth in Chinese capital investment in Cambodia was related to money laundering.

However, he reportedly went on to tell a media conference:

"Should the news of money laundering be true about Chinese investments in Cambodia, China strictly opposes such act and will definitely take measures against those cases."

Casinos for foreigners only

Adding to the local disgruntlement is a sense of cultural imperialism.

Cambodians are prohibited by their government from gambling, so the casinos are strictly for foreigners, and often staffed by foreign nationals.

And many establishments make little effort to fit in with the local culture.

There is nothing Cambodian about the glitzy Jin Bei resort, the largest licenced casino and hotel complex in Sihanoukville. It is signposted in Mandarin and boasts Chinese cuisine in its restaurants.

The Jin Bei Hotel and Casino Resort in the coastal town of Sihanoukville. ( ABC RN: Antony Funnell )

But how seriously such concerns are taken in Phnom Penh is arguable.

Corruption in Cambodia is endemic. Cambodia ranks at number 161 on Transparency International's 2017 Corruption Perceptions Index — among the 20 most corrupt countries on Earth.

And there is much personal wealth to be gained by well-placed Cambodians eager to court foreign interests.

In 2016, the UK-based transparency organisation Global Witness published an investigative report accusing Prime Minister Hun Sen and his family of amassing a personal portfolio of companies worth more than $US200 million.

On January 11, around the same time Governor Yun Min's report was sent to the capital, the government in Phnom Penh hosted an official visit by China's Premier, Li Kequiang.

The visit saw Premier Li and Prime Minister Hun Sen sign a series of 19 bilateral Memoranda of Understanding covering such diverse interests as cooperation on rice research, the restoration of the ancient ruins at Angkor Wat and the building of a new expressway between Sihanoukville and the capital.

China's Premier Li Keqiang met with Prime Minister Hun Sen in Phnom Penh in January. ( Getty Images: TPG )

Hun Sen's embrace of Chinese largess is also, in part, a geo-political move. Unlike the United States and the European Union, Beijing has no qualms with Hun Sen's increasingly authoritarian rule.

The Prime Minister, who has held power since 1985, is due to face an election later this year, but last November he successfully pressured Cambodia's Supreme Court to dissolve the main opposition party, the Cambodian National Rescue Party.

The move all but guarantees his victory come the national poll in July, and has been described by the International Commission of Jurists as "political theatre".

Two months before that, his government jailed the CNRP's leader, Kem Sokha, on charges of treason, alleging he was secretly plotting a coup with American backing.

Australia urged to rethink relationship

For the Cambodian nation and its people, Hun Sen's pivot toward China risks making the country increasingly subservient to Chinese wishes and further isolates it from long-time Western donors.

The US has now signalled it will be cutting aid funding in response to Hun Sen's latest political manoeuvrings.

Exiled senior opposition figure Mu Sochua has urged Australia to also rethink its relationship with Phnom Penh, ahead of this weekend's ASEAN conference in Sydney — a gathering Hun Sen is expected to attend.

"Australia's policy has always been to engage with Hun Sen," she told the ABC.

"This engagement for the past 25 years has not shown anything but reinforcing Hun Sen's power."