A second potential case of H5 bird flu in South Australia has been submitted for further testing, with authorities describing it as an unconfirmed but "suspected" detection in a migratory seabird.

A giant petrel bird has been confirmed to be infected with the deadly H5N1 bird flu virus, the first case on Australia's east coast.

Six infections have been confirmed across 3 states, including in a seabird called the giant petrel found near the seaside town of Hawks Nest in New South Wales | World News