South Korea has seized thousands of smuggled drug capsules filled with powdered flesh from dead babies, which some people believe can cure disease.

The capsules were made in north-east China from babies whose bodies were chopped into small pieces and dried on stoves before being turned into powder, the Korean customs service said.

Officials refused to say where the dead babies had come from or who made the capsules, citing possible diplomatic friction with Beijing. Last year, Chinese officials ordered an investigation into the production of drugs made from dead foetuses or newborns.

The customs service said it had discovered 35 attempts since August to smuggle a total of about 17,450 capsules.

The smugglers told customs officials they believed the capsules were ordinary stamina boosters, and were ignorant of the ingredients and manufacturing process. Ethnic Koreans from north-east China who now live in South Korea intended to use the capsules themselves or share them with other Korean-Chinese, a customs official said.

The capsules were carried in luggage or sent by international mail. They were all confiscated but no one was punished because the amount was deemed small and they were not intended for sale, the official said.

The customs agency began investigating after receiving a tip a year ago. No sicknesses have been reported from ingesting the capsules.