A bomb disposal unit was called to Dunedin museum after the discovery of an explosive acid this afternoon.
A police spokeswoman said emergency services were alerted about a threat at Toitu Otago Settlers Museum in Queens Gardens at 3.10pm.
Members of the NZ Defence Force's Explosive Ordnance Disposal were removing picric acid from the museum, she said.
Police worked to keep the public away from the site, she said.
A similar incident occurred in Nelson earlier today after the acid was found in the Founders Heritage Park museum.
Picric acid is used in the production of explosives, matches, and electric batteries. It's also used in etching copper and manufacturing coloured glass, in the leather industry, and in the synthesis of dyes.
The acid, also known as also called 2,4,6-trinitrophenol, is very unstable and a flammable/combustible material.