Anthrax may be the cause of death of three drug users, it was revealed yesterday night.

UK health officials disclosed that a second person confirmed as having anthrax contamination has died. And a third person who may have been contaminated has also died. But two other drug users with anthrax are alive and responding well to treatment. The developments were disclosed by NHS Greater Glasgow and Clyde health board. Officials said the board was working with police and colleagues at the neighbouring Lanarkshire health board to try to identify the source of the disease.

It is possible that contaminated heroin, or a contaminated cutting agent mixed with heroin, was responsible.

Dr Syed Ahmed, consultant in public health medicine, said: "There have been no new drug-injecting heroin users with infections admitted to hospitals in the west of Scotland since the weekend.