Undersecretary for Security Michael Cheuk said on Tuesday that the number of suspected Hong Kong victims of Southeast Asia trafficking gangs has risen by one, to 38.

Cheuk told a Metro Radio programme that 21 people are believed to be still being held captive in Myanmar and Cambodia and the rest have either returned to Hong Kong or are safe abroad.

He said Chinese embassies in the region and the SAR's economic and trade office in Bangkok are working to secure the safety of those Hongkongers in trouble.

The security official also called on people not to send prank messages to a WhatsApp number the government has set up for reports about Hongkongers being held captive overseas, saying most of the messages received so far have been irrelevant.

All but one of the suspected trafficking victims fell prey to online job scams, officials said. Some people have reportedly been beaten after trying to escape gangs forcing them to take part in boiler room scams.