Napier's museum and library are closed after a "substance of concern" was located.
A police statement said it's understood the substance had been in the museum for a significant period of time.
The statement said the museum has been closed to the public as a result. The Napier library, in the same building as the museum, is also closed.
"An NZ Defence Force explosive ordnance disposal team is currently en-route from Wellington to assess the situation," police said.
