Four members of staff have been suspended at a hospital trust where police have launched an investigation into the death a patient.
It follows an allegation made about the care of a man in his 40s at Hellesdon Hospital near Norwich.
The patient had a medical emergency on 1 October and questions have been raised over the treatment he received at the mental health hospital before he was taken to the Norfolk and Norwich University Hospital.
He died three days later.
Roz Brooks, of Norfolk and Suffolk NHS Foundation Trust, said it had contacted police as soon as concerns were raised.
She added: "We can confirm that four members of staff have been suspended pending further investigation." The trust has launched an internal investigation.
Police in Norfolk say an allegation has been made about the care a patient received at a Norwich hospital before he died.
A man in his late 40s, who had been receiving treatment at Hellesdon Hospital, had a medical emergency on Tuesday 1 October.
He was taken to the Norfolk and Norwich University Hospital, where he died three days later.
Detective Chief Inspector Tracey Little said the allegation related to "the care the patient received prior to and during the medical emergency" at Hellesdon Hospital.
"A Home Office post-mortem examination has been carried out but proved inconclusive and further tests will now be carried out," she added.
The death is being treated as unexplained.
Police said the investigation was not linked to "any other enquiries being undertaken by the Major Investigation Team".