Police have closed an investigation into a suspected arson attack at a hospital building.

Crews from across the county were called to Drayton High Road, Hellesdon on Sunday, May 7, where firefighters tackled a blaze at Hellesdon Hospital.

On May 9, police confirmed they were investigating the incident as suspected arson, however, it has since been closed.

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Norwich Evening News: The fire happened in a derelict building at Hellesdon HospitalThe fire happened in a derelict building at Hellesdon Hospital (Image: Newsquest)

A police spokeswoman said: "All lines of enquiry have been exhausted and the case has been closed.

"Of course, we would always review any new information provided to us."

READ MORE: Hethersett school fire being treated as arson, police confirm

Norwich Evening News: A police spokeswoman said All lines of enquiry have been exhausted and the case has been closedA police spokeswoman said All lines of enquiry have been exhausted and the case has been closed (Image: PA)

READ MORE: Work under way on £50m Hellesdon Hospital revamp project

Lawrence Railton, who lives in Carter Road, was first on the scene.

The 56-year-old said: "There was so much smoke rolling out from one of the upstairs windows.

"Flames began to flicker out from the top floor window while black smoke was pouring out of the edges of some of the surrounding, boarded up, windows."

Work recently started on a £50m revamp of the Hellesdon Hospital site, which is the headquarters of the region's mental health service the Norfolk and Suffolk Foundation Trust.

Norwich Evening News: The fire took place inside a derelict building at Hellesdon Hospital on May 7The fire took place inside a derelict building at Hellesdon Hospital on May 7 (Image: Newsquest)