Scientists have been investigating reports that six people have fallen ill after working near a controversial police radio mast in Norfolk.
The Tetra mast at North Walsham Police Station
The new communications mast, which is used for the Tetra emergency system, is near North Walsham police station.
Police confirmed six officers and civilian workers had reported symptoms including dizziness and headaches.
A spokesman said scientists have confirmed the building is safe but would continue monitoring the six.
The Tetra system, which provides better security and coverage for the emergency services, is already working in Suffolk and Cambridgeshire where no problems have been reported.
However, some residents living near the mast in North Walsham told BBC Look East they too were suffering from ill-health since the mast was switched on.
Matthew Pennington said he had been suffering from headaches similar to a mild hangover.
Insp Mick Lamb, of Norfolk Police, said scientists had carried out a radiological sweep of the police station and pronounced there was no health risk there.
He added that the system was also being monitored for health effects across the country in a study involving about 1,000 officers.