The Ministry of Social Development office in the Christchurch suburb of Linwood went into lockdown this morning.
File image. Photo: RNZ/ Rebekah Parsons-King
A spokesperson said the move followed a threat, and the office has since reopened.
They said the safety of staff and clients were their top priority and referred all further comment to the police.
Police said they were called to the office just 9am and were now speaking to a person in relation to the incident.