The bird had reportedly gone missing during a race in the US state of Oregon in late October before it was found in Melbourne almost after two months.

But as per the officials, the pigeon, which has been named Joe, poses a "direct biosecurity risk" to Australia's bird population and poultry industry.

Authorities are planning to catch and euthanize the bird.

Melbourne resident Kevin Celli-Bird reported that he found the pigeon in his back garden on 26 December.

"He was pretty emaciated so I crushed up a dry biscuit and left it out there for him," he told the news agency.

Some internet research led Celli-Bird to discover that the bird, which is registered to an owner in Alabama, was last seen during a pigeon race in the western US state of Oregon.

But after news of Joe's appearance made news in Australia, Mr. Celli-Bird was contacted by officials who were concerned about the threat of infection.

The pigeon has not yet been caught, but the Department of Agriculture, Water, and the Environment is saying that it will have to be put down because of the threat it poses to local birds.

"Regardless of its origin, any domesticated bird that has not met import health status and testing requirements is not permitted to remain in Australia," a department spokesperson quoted in a statement.

"The only possible outcome to manage the biosecurity risk is humane destruction of the bird."

However, it is not clear yet how the bird managed to complete the 8,000-mile journey from the west coast of the US to southern Australia, but officials believe he probably hitchhiked on board a cargo vessel.

While it is possible to legally bring pigeons into Australia, the process is very complicated and can cost tens of thousands of dollars, and none have been legally imported from the US in over a decade.

Joe, the pigeon is not the first animal that had to face trouble from Australia's strict animal import laws.