Some crystal methamphetamine seized in a huge drug bust in China used the popular cold medicine Contac, manufactured by beleaguered British drugmaker GlaxoSmithKline (GSK), state media reported Tuesday.
The raid in the southern province of Guangdong, announced by state media last week, netted three tonnes of "crystal meth" in Lufeng city, said to account for one-third of China's production of the drug.
Some makers extracted pseudoephedrine from Contac, even employing students to empty the powder from the capsules as part of the process, the Global Times newspaper reported.
Chinese authorities have already put GSK under scrutiny over an alleged bribery case, detaining four executives of the British company last year.
GSK did not confirm the media report, but said it was concerned about any illegal use of its medicines.
"As a responsible manufacturer, GSK is very concerned about any criminal activities which divert the use of our medicines for illicit purposes, and (we) vow to work with the appropriate authorities to ensure that we play our part in eradicating this criminal activity," it said in a statement provided to AFP.
Regulations require customers' names and identity card numbers to be registered before they can buy the medicine, sold under the name Contac NT in China, and put limits on the amount that can be purchased, the statement said. A higher strength form requires a doctor's prescription.
Paramilitary troops and police officers used helicopters and speedboats in the drug raids, which also saw 23 tonnes of raw materials seized and nearly 200 suspects from 18 drug rings arrested, the official Xinhua news agency has reported.
Methamphetamine is the second most popular drug in China after heroin, according to a report last year by the United Nations Office on Drugs and Crime (UNODC).