Staff at the Norwich Research Park were on lockdown as the police hunted for an arrested man who escaped from hospital.
It happened around 11.45am on Wednesday, when police told staff at the John Innes Centre not to leave the premises while they search for a man who had been arrested for public order offences.
Staff were confined to their offices while the hunt was carried out.
The missing man had been receiving treatment at the Norfolk and Norwich University Hospital (NNUH) but fled at around 11.35am.
A Norfolk police spokesman said as of Wednesday afternoon the man was still on the loose, with officers continuing their search.
An NNUH spokesman said they were unable to comment because of patient confidentiality but said that they had a security team in place.
However he did confirm if convicted prisoners were treated at hospital they were handcuffed and escorted by officers.
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