BRITISH authorities today warned drug users that heroin in London was highly likely to be contaminated with anthrax, after a first confirmed case there and following nine deaths in Scotland.

"While public health investigations are ongoing, it must be assumed that all heroin in London carries the risk of anthrax contamination," said Dr. Brian McCloskey, who is director of the Health Protection Agency (HPA) in London.

"Heroin users are advised to cease taking heroin by any route, if at all possible, and to seek help from their local drug treatment services."

McCloskey added that the risk to the general population was "negligible."

Anthrax has been found in 19 heroin users in Scotland since December and nine of those people died, six of them in the Glasgow area, officials said.

The first case in London was confirmed yesterday, and the user was in hospital receiving treatment.

"Similarities to the cases in Scotland suggest that the heroin, or a contaminated cutting agent mixed with the heroin, is the likely source of infection," a spokesman for the HPA said.

Last month, the French health ministry issued a warning about contaminated heroin, noting the Scottish cases and one other case in Germany, and saying the drug could also be circulating in other European countries.

Anthrax is a potentially lethal bacterium that exists naturally in the soil and can also occur among cattle.

It is also, more notoriously, a potential bio-terror weapon.

