A dangerous batch of amphetamines could be responsible for putting three people from Powys in hospital.
Dyfed-Powys Police have issued a warning after people suffered from the adverse effects of the drug in Welshpool.
The three have now been discharged from hospital, but officers said without medical attention some could have died.
A 27-year-old local man has been arrested on suspicion of supplying the drugs and is on police bail.
Officers are urging drug users to refuse all offers of drugs in the area.
Det Insp Owain Richards said: "Dyfed-Powys Police work closely with partner agencies in the county through the community safety partnership to protect families and communities from substance misuse through prevention, enforcement and treatment, and a multi-agency approach is being taken to these incidents."
Anyone with information is asked to call Dyfed-Powys Police on 101 or Crimestoppers anonymously on 0800 555 111.