A Cambodian court on Friday charged 33 surrogate mothers paid to deliver babies for Chinese couples with cross border human trafficking, an official said, refusing them bail on accusations that can carry a 20-year jail term.
The women -- many of whom are pregnant -- were discovered last month during a raid by Cambodian authorities on an illegal surrogacy business in Phnom Penh.
Five people, including a Chinese national, were arrested and have already been charged with human trafficking.
The women were charged on Friday with human trafficking and a judge "placed 32 surrogate mothers in jail" pending further investigation and trial, said Ly Sophana, a spokesman for Phnom Penh Municipal Court.
The remaining woman did not appear in court on Friday.
The women face up to 20 years in jail, according to the human trafficking law.
China's easing of its one-child policy two years ago has seen demand spike for fertility clinics, with figures estimating that 90 million women became eligible for another child after the rule was relaxed.
But surrogacy is illegal in China, forcing those who can afford it to look for potential options abroad.
Southeast Asia was long a popular international surrogacy destination, with cheap medical costs, a large pool of poor young women and no laws excluding gay couples or single parents.
But in recent years countries in the region have cracked down on the trade, following a series of scandals and criticism that the business exploited poor women.
Cambodian authorities banned the practice in 2016 after prospective parents turned to the impoverished country in the wake of a ban in neighbouring Thailand the previous year.
An Australian nurse jailed for 18 months for running a surrogacy clinic in Cambodia had her sentence upheld in January in a prominent case highlighting the country's role in the trade.