The Work and Income building on Pukuatua St was in lockdown police have confirmed.
A police spokeswoman said they received a call at 9.05am but she could not confirm any other details.
Police have since been able to confirm the building went into voluntary lockdown as a precaution following a threat by a person through a phone call to the call centre.
"The office went into voluntary lockdown as a precaution. The police have managed to locate and arrest the person who issued the threat," a police spokeswoman said.
A client in the building at the time said everyone was asked to move to the centre of the room away from the windows.