The deadly H5 variant of avian influenza has been detected in a bird that washed up on a remote beach in Western Australia's south, the first time the disease has been found in Australia.

The H5 avian influenza has never been detected on mainland Australia before — the last continent on Earth without a confirmed case.

Agriculture Minister Julie Collins announced on Friday a bird has died and the initial test was positive for H5N1. Further tests will be performed for confirmation.

Migratory seabird known as brown skua tests positive for avian influenza