A crewman's in a critical condition in hospital as firefighters continue to battle a blaze on the world's largest purpose-built livestock carrier in Australia.

The fire broke out in the accommodation area of the ship at Freemantle Port in Perth this morning.

All crew members have been evacuated and there are no livestock on board.

A man in his 40s was rushed to Fremantle Hospital with burns and smoke inhalation and is in a critical condition.

Two other people have been taken to hospital in a stable condition.