Search operations are ongoing to find the remainder of the 41 Chinese nationals who were aboard the vessel, while two Cambodian sailors involved in the incident have been arrested.
Two Cambodian crew members abandoned their boat with Chinese nationals on board as it sank in the Gulf of Thailand, leaving at least one person dead and more than 20 missing, authorities have said.
The boat with 41 Chinese people on board got into difficulties off Sihanoukville a day earlier, provincial spokesperson Kheang Phearom told AFP news agency on Friday.
Phearom said 19 people have been rescued and the body of a woman recovered from the water, adding that officials are searching for the others.
Provincial police chief Chuon Narin told pro-government media outlet Fresh News that a representative of the group told police they left China from a port in Guangdong province by speedboat on September 11.
Nearly a week later, they were transferred to a wooden boat with two Cambodian crew members in international waters, the police chief said. That vessel began to sink after breaking down on Thursday.
He said a fishing boat picked up the two Cambodians and left, abandoning them and their boat in the sea.
According to Phearom, the Cambodians had been detained for questioning.
The once-quiet fishing village of Sihanoukville has been transformed by a Chinese investment boom in recent years, with dozens of casinos opening.
Chinese Foreign Ministry spokesperson Wang Wenbin said Beijing was in "close contact" with Cambodian officials and requested "that the Cambodian side make full efforts to carry out search and rescue operations, and quickly confirm and find out relevant circumstances."
Cambodian authorities have been trying to crack down on people-smuggling and trafficking networks following widespread reports of people from other Southeast Asian countries being tricked into migrating for job opportunities billed as lucrative.
There have been multiple recent reports of Chinese workers being duped into working in casinos or online scam operations in Sihanoukville and prevented from leaving.
Police and immigration officials raided a compound in the city earlier this month and detained more than 140 foreigners working illegally, 130 of them Chinese.
Officials said they had found evidence of illegal confinement and torture, illegal gambling, prostitution and human trafficking.
Along with thousands of mobile phones and hundreds of computers, officers also seized handcuffs, electric batons and electric shock equipment.
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