Dozens of alleged human trafficking victims fled from an 'illegal casino' in Cambodia where they were allegedly abused by their employer.

Footage shows how 42 Vietnamese nationals sprinted out of the Chinese-run gambling den before forcing their way through baton-wielding guards to escape miserable working conditions in Kandal province on August 18. They then leapt into the Binh Di river and tried to cross the border into Vietnam, authorities said.

Long Binh border officer Major Le Ngoc Tuan said officials have rescued 35 men and five women. The refugees said one of them had been swept away by the current, while another had been caught by the casino's guards.

The runaways were said to be workers of the Golden Phoenix Entertainment Casino in Cambodia's Kandal province, where they were reportedly forced to work long hours without pay.

Casinos in Cambodia are often funded by Chinese developers who lure wealthy holidaymakers from China - where gambling is illegal - to spend large sums. Many of the casinos are also used to launder money from drug production in Myanmar.

Speaking to Vietnamese media, one unnamed female survivor, 20, said: 'Our four months being cheated while working at a casino in Cambodia were like hell. If I did not do it, I would be beaten to death.'

Cambodian Interior Minister Sar Kheng said: 'These people might have been working here illegally.

'They were promised salaries, but they did not get what they were promised. They crossed back to Vietnam because they could not reach a deal. They fled the place.'

Police are now investigating the incident and have detained a casino manager in custody, he added.

Sar Kheng said Cambodia has launched nationwide immigration checks on foreigners living in the country, which has become a hotbed of trafficking for migrants scammed by the promise of lucrative jobs, only for them to become slaves in boiler room call centres, illegal casinos, brothels and other underground enterprises.