A growing number of foreigners have been involved in drug trafficking in the country, latest figures from Chinese courts and customs showed.

Local courts in the Chinese capital tried 36 cases of drug trafficking that involved foreigners last year, 12 times the number in 2006, the Beijing Higher People's Court said on Thursday, two days before the International Day Against Drug Abuse and Illicit Trafficking.

The drugs trafficked by the foreign defendants were mostly heroin and methamphetamine of high purity, with the drugs trafficked by each foreign suspect weighing an average of more than 1 kg, the court said.

The total amount of drugs presented in the trials of foreigner-related drug trafficking cases also jumped from 9 kg in 2006 to 54 kg in 2008.

"The proportion of female foreigners among all the foreign defendants in drug trafficking cases also rose from 9 percent to 30 percent over the past few years," the court said.

"The problem of foreigners smuggling drugs is getting worse," it said.

In Guangzhou, capital of Guangdong Province, four out of 10 drug trafficking cases sentenced by the Guangzhou Intermediate People's Court on Thursday alone involved foreigners.

The Guangzhou Intermediate People's Court said the accused foreigners carried drugs totaling 6.5 kg.

The Haikou Customs in the southern province of Hainan said on Thursday that more women from Southeast Asian and African countries have also been caught in drug trafficking in the province.