A Hampshire police station’s custody unit has been closed following a suspected leak of an unknown substance.

Officers were alerted to the incident at Andover police station at 2.30am today when custody staff and detained persons began complaining of headaches and nausea.

The station was evacuated with the five detainees transferred to another custody centre.

Hampshire Fire and Rescue Service attended with their hazardous materials specialists.

South Central Ambulance Service was also called to the scene.

Six members of Hampshire Constabulary and the five detainees were examined by medics from SCAS.

Nobody needed hospital treatment and all officers remained on duty.

The cause of the leak, which is contained within the custody unit, will continue to be investigated by specialist engineers today.

The custody unit will remain closed until further notice while the rest of the station will operate as usual.

A police spokeswoman said: "Hampshire Constabulary would like to stress that this incident is not thought to be suspicious and the public were not considered to be at risk at any time."