Ambassador Wang Wenbin urged Phnom Penh to strengthen a crackdown on the illicit industry in a meeting with Cambodia's top ministers, a statement on the embassy's WeChat account said.

"China is highly concerned about a number of recent cases involving Chinese citizens going missing or disappearing in Cambodia," it quoted Wang as saying.

Most of the harmful cases involving Chinese nationals were related to online fraud, Wang said, adding they were "inconsistent with the traditional friendship between China and Cambodia".

The Cambodian government has said it is cracking down on the illicit industry, which employs at least 100,000 people in the Southeast Asian country, according to United Nations figures.

Initially largely targeting Chinese speakers, transnational crime groups have expanded operations into multiple languages to steal tens of billions annually from victims around the world.

Those conducting the scams are sometimes willing con artists, and sometimes trafficked foreign nationals who have been trapped and forced to work under threat of violence.

In recent months, China has stepped up its pursuit of key figures in the scam industry across Southeast Asia to try them on its own soil.

Phnom Penh deported Chinese-born tycoon Chen Zhi, accused of running internet scam centres in Cambodia, to China this month.

The UN Office on Drugs and Crime estimates online scams caused up to $37 billion in losses in East and Southeast Asia in 2023.

Amnesty International has accused the Cambodian government of "deliberately ignoring" rights abuses by cybercrime gangs.