Two endangered Hector's dolphins have been found dead in separate parts of the South Island.
The Ministry for Primary Industries (MPI) says the twin deaths are very concerning, as the dolphins may have been subject to human interference.
A member of the public found one dolphin on a Greymouth beach last month and reported it to the Department of Conservation (DoC).
Another dead Hector's dolphin was found near Banks Peninsula by a member of the public on Sunday.
Neither death had been reported as required under the law.