The Government of Western Australia (WA) on Tuesday is sending a robot to New Zealand to assist in the rescue operation for 29 miners, including two Australians, trapped underground at the Pike River coal mine in Southern Island.

An aircraft from New Zealand was expected to pick up the WA Water Corporation robot from Perth on Tuesday, a spokesman for WA Water Minister Graham Jacobs told Australian Associated Press (AAP) .

Early on Tuesday, a robot sent into the South Island mine broke down and rescue officials reported it could not be used again.

The WA Water Corporation robot was employed to travel along pipes, the water minister's spokesman said.

It is a "robust, skid-steered remotely operated vehicle, equipped with cameras, lights, communications and gas testing equipment".

The robot is controlled via a fibre-optic cable and has a range of up to 6 kilometers.

Technical staff at the state-owned Water Corporation Inspection Services had offered their time without pay to prepare the system if required.