Detectives have issued a warning about a “dangerous batch of cocaine” after a man died at a birthday party.
The 22-year-old victim became unwell after taking the drugs at a party in Colchester, Essex, on Saturday night.
He was taken to hospital but died shortly afterwards.
Three men, all from Colchester, Essex, were arrested on suspicion of drugs offences.
Two of them, a 20-year-old and 35-year-old, have been released under investigation while a third man, 20, is still being held on suspicion of being concerned in the supply of drugs.
A 20-year-old woman from Colchester, Essex, who also became unwell at the party remains in hospital in a stable condition.
Police said she has been assisting police with their inquiries.
Det Insp Kev Hughes, of Essex Police, said: “We are concerned there may be a potentially dangerous batch of drugs being sold in the area which pose a direct threat to the safety of those who’ve bought them and are using them.
“We understand members of a birthday party were out drinking in the Shrub End area of Colchester yesterday, at some point during the evening cocaine was purchased and taken by some people at the party.
“I have concerns for the safety of anyone whom may have bought cocaine in Colchester or surrounding areas in the last 24 hours or so, and would appeal to you not to take it.”
He said anyone feeling unwell after taking the drugs should seek immediate medical attention.
Essex Police said the death at present was being treated as unexplained.
By Rachel McDermott