Police in Norfolk are investigating an allegation that an elderly patient died of a drug overdose at the James Paget hospital in Gorleston last week.
Detective Chief Inspector Paul Durham, senior investigating officer, said:
We are investigating an allegation that a drugs overdose was administered to a patient, leading to his death.
A Home Office post-mortem, carried out earlier this week, determined the cause of Mr May's death as heart failure and we now await the results of further toxicology tests which will help inform our inquiry.
We understand that this news may generate concern and it's important for us to underline that our investigation, which is still at an early stage, is based on a single report of an isolated incident and that the hospital trust is co-operating fully with the investigation.
Police said the investigation is being led by a joint Norfolk and Suffolk major investigation team.