The Hastings Opera House has been closed following engineering advice that the building is earthquake-prone.
Hastings mayor Lawrence Yule says an engineering report in 2013 advised the building was safe but that further investigation was needed.
He says that work has been completed and the building has now been classified as quake-prone.
Mr Yule says council is surprised by the result given the quake-strengthening that was commissioned as part of an upgrade in 2004.
The theatre will be closed until mid-May this year to allow further engineering investigations, but some businesses located in the building complex will continue to operate.