A man has died in hospital shortly after becoming unwell while being detained by Norfolk police officers, prompting an official investigation into his death.

Officers were called to Cotman Close, Diss, at 12.45pm on Monday, August 10 after receiving reports of a man acting suspiciously.

He was detained in Victoria Road outside Morrisons under the Mental Health Act, but soon became seriously unwell.

Paramedics attended the scene and the man was taken to the Norfolk and Norwich University Hospital (NNUH) for treatment.

The man has since died and the matter, which had previously been referred to the constabulary’s Professional Standards Department and the Independent Office of Police Conduct (IOPC), is being investigated.

An IOPC spokesman said: “We have launched an independent investigation into the circumstances surrounding the death of a man, on Tuesday, who had been detained by Norfolk Police.

“An ambulance was called, which took the man to Norfolk and Norwich University Hospital, where he sadly died at 12.10am.”

The IOPC spokesman said they were now appealing for witnesses “following the restraint of a man by police officers” on August 10.

He said an ambulance was called and took the man to hospital where he sadly died on Tuesday, August 11.

The spokesman added that after a mandatory referral from Norfolk Police, we sent investigators to the scene and to the post incident procedure.

“We have begun gathering statements from officers and witnesses and will be analysing CCTV in the area.”

Sarah Green, IOPC regional director, said: “My thoughts are with all those affected by this tragic incident.

“Our role when someone has died following police contact is to establish all of the circumstances surrounding how the incident occurred.

“We are continuing to gather evidence and are keen to speak to anyone who was in the area at the time of the incident and may have witnessed something.”

We would appeal to anyone who witnessed the incident to contact us and assist with our independent investigation.

Call 0300 303 5728 or email victoriaroaddiss@policeconduct.gov.uk if you were a witness to the incident and have any information about it.