A second man has died after a so-called bad batch of heroin was circulated.
Police declared a major incident in North Devon on Friday and said a batch of the drug had made people "very ill".
Devon and Cornwall Police said 10 people were taken to hospital after incidents in Westward Ho!, Barnstaple and Bideford, with one dying.
The force said two men and two women detained on suspicion of being involved in the supply of a controlled substance have been released on bail.
Related Internet Links
The BBC is not responsible for the content of external sites.