THREE people were rushed to hospital in Huddersfield after police believe they took contaminated heroin.
A 38-year-old man, a 26-year-old woman and a 32-year-old man were in Moldgreen when they all collapsed after taking the class A drug on Monday night.
The 38-year-old man is still at Huddersfield Royal Infirmary where he is said to be in a stable condition.
The other two have been allowed home after treatment.
Police are warning heroin users to be extra vigilant as they believe a contaminated batch of heroin could be in circulation in town.
Earlier this year an alert was sent to hospitals, ambulance services and GPs after a batch of heroin contaminated with anthrax killed 14 drug users across the UK.
The contaminated drug is still feared to be circulating in Scotland, with Health Protection Scotland (HPS) saying the most recent cases were over the May Day bank holiday weekend.
HPS said there was no way for users to tell if heroin was contaminated and they can become infected with anthrax from both injecting and smoking the addictive drug.
Symptoms include swelling and redness at the area of injection, which gradually turns into an abscess or ulcer.
Users affected by anthrax may also experience headaches and nausea.
If anthrax is present in heroin that is smoked users may have breathing difficulties, sickness and flu symptoms.
Heroin users need to act quickly if they fear they have been infected with anthrax and seek medical advice straight away.
Anyone with information about the suspected contaminated batch or drug dealers should contact West Yorkshire Police on 0845 6060606 or Crimestoppers anonymously on 0800 555111.
Kirklees Lifeline staff are on hand to give help and support to drug users who want to quit using heroin or begin using a safer alternative like methadone.
People needing help or advice can drop in at the Huddersfield office on Station Street or call 01484 353333.
The Dewsbury office on Wellington Street can be contacted on 01924 438383.