PART of a council headquarters was evacuated yesterday after an office worker received a suspicious package.

A section of the education department, on the third floor of Durham County Council’s County Hall, in Aykley Heads, Durham City, was sealed off at about 10am after a member of staff raised concerns over a suspicious envelope.

The police, fire and ambulance services were called, with at least three fire engines, an ambulance and police officers attending.

Police said the envelope contained a non-harmful substance that had not posed a risk to staff or the public.

However, police have launched an investigation into the nature and origin of the envelope. The incident lasted about three hours.

Most of County Hall remained open throughout the incident.

Independent Weardale councillor John Shuttleworth has criticised what he said were cutbacks to security at County Hall.

Earlier this month, Comeleon House, an office building on Tanfield Lea industrial estate, near Stanley, was evacuated when a council worker reported an allergic reaction after opening an envelope.

A search of the building found no noxious or harmful substance.

Last month, a man was arrested and bailed pending inquiries after a substance thought to be rat poison was posted to a council worker, along with a threatening note.

In a separate incident, hundreds of people were evacuated from their office after a mystery white power was sent in an envelope to the Student Loans Company, at Lingfield Point, in Darlington. A woman who opened it became ill and had to be treated by paramedics at the scene.

There are no known links between the incidents.