General Keo Vannthan, Immigration Department spokesman, told Cambodian media on Monday that he had led a team to Golden Phoenix Entertainment Casino in Chrey Thom Commune, Koh Thom District, Kandal Province and detained the manager for questioning, Khmer Times reported.

The inspection resulted in the arrest of the casino manager, a Chinese national whose identity has yet to be revealed.

It was made following the escape of 42 Vietnamese workers from the casino last week.

They swam across the Binh Di River, the natural border between Vietnam and Cambodia, to return to Vietnam's An Giang Province due to their imprisonment and torture.

A total 40 succeeded, but one of them, by the water and another was recaptured by casino guards. Of the 40, five are women and the rest, men.

The successful escapees said they went to Cambodia and worked at several casinos in online gaming, but had been overworked and not given pay or rest, and so decided to illegally cross the border back into Vietnam.

General Vannthan said the Chinese manager admitted to "forcing the group to work against their will" but claimed that the escapees owed the company money.

He added that Cambodian authorities have questioned 11 other Vietnamese who also work at the casino but failed to run away.

They said the company promised to pay them $800, but that the manager had paid the workers only $400 or $500 a month, sparking a dispute that prompted the escape.

None of the 11 workers that were questioned have a passport.

Dinh Van Noi, director of An Giang police, said the victims revealed more than 2,000 Vietnamese had been smuggled to Cambodia to work in casinos.

Noi proposed last Saturday that the Ministry of Public Security establish a national mission to investigate the smuggling of Vietnamese to Cambodia.

Many Vietnamese have been tricked into going to Cambodia to work for casinos and similar places where they are often exploited.

If they want to return to Vietnam, they have to pay the casinos up to $30,000, authorities said.

In the first half of this year, Vietnamese and Cambodian authorities collaborated to rescue over 250 such workers.