Invercargill Police attended an incident at the administration block of the Invercargill Prison this morning after a staff member opened a letter to find an unknown quantity of white powder inside the envelope.
The Fire Service initially attended the incident, which occurred around 8.35am and Invercargill Police were called to assist.
The prison's administration block, where the incident occurred, was secured by Police, Corrections staff and Fire. The block is a separate building to the prison itself.
Three administration staff in the immediate vicinity of the scene - including the person who had opened the envelope - were put through a decontamination process as a routine precaution.
There was no immediate or potential danger to any other staff, members of the public or prisoners, and the administration block was soon cleared and staff were able to return to work.
The powder has been secured and seized and Police are making inquiries to determine what it is.
ENDS
Released by Acting Senior Sergeant Deon McNaught, Invercargill Police