HONG KONG - Six Malaysians have been arrested in Hong Kong for attempting to bring nearly HK$4 million (S$690,240) worth of ketamine into the city, apparently by masquerading as tourists, the city's media reported.

The six Malaysians, who are aged between 18 and 28 and were travelling as part of a tour group, were intercepted for inspection at the Hong Kong International Airport's customs clearance counter after arriving from Kuala Lumpur on Wednesday, South China Morning Post said on Thursday (Nov 30).

"More than 8 kilograms of suspected ketamine was found strapped to the bodies of four of the six men," a source with the knowledge of the case was quoted by the newspaper as saying. "The haul had an estimated street value of HK$3.9 million."

The source said it was possible drug dealers believed members of a tour group would be subjected to less scrutiny.

Another source interviewed by the Post noted that most ketamine seized in Hong Kong has been smuggled from mainland China, and the Malaysian bust may indicate that dealers are setting their sights elsewhere.

"We believe a massive crackdown against underground drug manufacturing plants on the mainland led drug dealers to find new source of the drug and use new smuggling routing into Hong Kong," the source said.

He said officers were investigating whether the consignment was smuggled into Malaysia before being brought to Hong Kong and how the six young suspects were recruited.

In Hong Kong, trafficking in a dangerous drug carries a maximum penalty of life imprisonment and a HK$5 million fine under the Dangerous Drugs Ordinance

Latest figures show local authorities seized 110kg in the first 10 months of this year, down 62.5 per cent compared with 293 in the same period last year, the Post reported.