STOCKHOLM (AFP) - Sweden's food safety watchdog said on Tuesday it had found "extremely high" levels of arsenic in a Chinese herbal remedy, posing a "very serious health hazard."

The toxic substance was found in a product called Niu-Huang Chieh-tu-pien, which is claimed by online vendors of traditional Chinese medicine to cure numerous conditions, including toothache, skin infections, anorexia and fever in infants.

The product is also sold under the Indian names Divya Kaishore Guggul and Chandraprabha Vati.

"The recommended dose provides a daily amount of inorganic arsenic which in a worst case scenario equals half a lethal dose," said Mr Leif Busk, a toxicologist at the National Food Agency.

"Consequently, anyone who eats it can be very seriously affected. It's frightening to think there are companies selling these very hazardous preparations."

The product was discovered and removed from shelves in Stockholm this summer, but could still be on sale in other Swedish cities. It can also be bought on the Internet.

Local authorities in Stockholm have issued a warning to other European countries through an EU alert system, according to the agency.