Kuala Lumpur - Malaysian police have detained four Taiwan men and seized more than 430 kilograms of drugs worth 61.3 million ringgit (16.5 million dollars) in the country's biggest seizure of the hypnotic drug Nimetazepam, a news report said Tuesday.

Police also detained six locals in Sunday's pre-dawn raid on a factory in the southern Johor state, said federal narcotics chief Zulhasnan Najib Baharuddin.

"The Taiwanese were in the midst of processing the Erimin 5 when police stormed the factory," Zulhasnan was quoted as saying by the Star daily.

Nimetazepan, also known as Erimin or Eramin 5, originally used to treat insomnia, is often sold in Asia to drug abusers as a substitute for Ecstasy.

Police also seized machines used to process the drugs, about 430 kilogrammes of fine and coarse drug powder, and thousands of pills, he said.

Zulhasnan said the drugs were believed to be meant for distribution nationwide, adding that the suspects would be charged with drug distribution.

If found guilty, they will face the mandatory death sentence by hanging. (dpa)