The Department of Corrections office building in Dunedin was closed for several hours after a suspicious package was found.
A police spokeswoman said the package was reported to them about 10.15am on Thursday.
The building, including a retail premises on the ground floor, was evacuated as a precaution.
At 8pm, police revealed the package had been examined by the New Zealand Defence Force Explosive Ordnance Disposal Team and was found to contain items that were not of any concern.
"The cordons have been stood down and the building released back to occupiers," a spokesperson said.
An investigation into the circumstances of this incident is ongoing.
Powerball has now rolled over to $10 million for Wednesday night's draw.