Stockton drugs deaths: Six dead after taking heroin
The deaths of six people have been linked to a batch of low grade heroin that has been circulating on Teesside.
Three people have been arrested following the death in hospital on Wednesday of a man aged in his 40s - the latest linked to the inquiry.
A man and a woman, both 37, from the Stockton area also died after taking the drug, on 3 March.
In February, three people died in the space of a week after taking the drug, Cleveland Police said.
The force said it was advising drug users to take "extra precautions" and was working with agencies to find the supplier of the drugs.
Two women, aged 30 and 33, and a man aged 26 were detained on suspicion of administering a noxious substance, in connection with the latest death.
Det Insp Jon Tapper said: "I would reiterate that, whilst we don't advocate that anyone should buy any type of drugs, there are still batches of particularly harmful heroin in Stockton which are being peddled by dealers.
"Lives are being put at risk by accepting this particularly dangerous heroin and, sadly, there has been a further death in the area. We are concerned and would urge drug users to take extra precautions."