An Australian official has demystified the crop circles in Tasmania's legal poppy plantations saying they were formed by wallabies that walked in circles after getting high from eating the opium plant.

Tasmanian Attorney-General Lara Giddings made the explanation while addressing the security issues at the state's poppy fields during a budget hearing in parliament Wednesday.

"The one interesting bit I found recently in one of my briefs on the poppy industry was that we have a problem with wallabies entering poppy fields, getting high as a kite and going around in circles," Giddings told the budget committee, according to the Times Online.

The attorney-general's spokesman claimed his boss was just joking but poppy farmers admitted that wallabies, which are cousins to the kangaroos, jumped over fences and eat poppy heads.

Rick Rockliff, the field operations manager of poppy seed producer Tasmanian Alkaloids, laid credence to what farmers have observed saying he once saw a deer acting strangely in the field during harvest.

Times Online also quoted Rockliff as saying that sheep and other livestock that grazed on the field after harvest "would all follow each other around in large circles."

The Tasmanian poppy fields produce and supply alkaloids for international pharmaceutical companies to make morphine and other opiate drugs.