Drugged-up wallabies are responsible creating some of Australia's crop circles, it has been claimed.

Wallabies in Tasmania are said to keep breaking into poppy fields and eating opium poppies - used to make morphine - which causes them to act strangely.

They then start hopping around in circles, bumping into each other and accidentally creating the sort of crop circle patterns normally associated with UFOs and aliens.

A government official said the UHOs (Unidentified Hopping Objects) had become a problem for the Australian poppy industry which supplies about 50% of the world's legally-grown opium.

They will try installing bigger fences but the problem is some of these wallabies can be "as high as a kite".