Addicts in Swindon are being warned a batch of potentially fatal heroin may be on sale in the town.

The contaminated drug identifiable by its orangey-pink colour has been mixed with the tranquilliser Valium, which greatly increases the risk of an overdose.

Drug workers say that some users have reported unusual side-effects after injecting the cocktail, including nausea and headaches.

Swindon drug czar Glenys Armstrong, who heads the town's Drug And Alcohol Action Team said: "The contaminated drug can slow the heart rate and suppress breathing and could be fatal.

"It also makes it more likely that users will slip into unconsciousness.

"Valium is not meant to be injected. In addition, the risk of nausea means users may be sick and could choke.

"If they must inject, addicts should use smaller amounts at first and always ensure someone else is present.

"If a user becomes unconscious, you should always call an ambulance. You should not be afraid to call for help, even if someone has taken heroin."

Besides having a distinctive colour, the tainted heroin emits a strong caramel smell when heated prior to injecting.

One addict a 27-year-old man who attends Druglink in Victoria Road said: "I've been on heroin for 12 years, and I have been given all sorts of stuff, curry powder, pepper, you name it.

"Dealers will use anything to make more money and they risk our lives in the process."

Druglink manager David Cork says clients have reported unusual side-effects.

"Just today, two said they experienced nausea and headaches, which they wouldn't normally get," he said.

"There is a strong possibility the contaminated heroin was to blame."

All drug treatment agencies in the town have been alerted.

Cases of the drug have been reported in other parts of the country, including Bristol.

Swindon's DAAT was alerted to the problem by the Bristol Drug Project.

Tamash Lal