The result of freaky winds, highly intelligent extraterrestrials or practical jokers? It may turn out that those intricate crop circles may be the work of two pranksters. David Chorley is the artist who claims to be one half of the force behind those mysterious imprints in southern England. Armed only with two pieces of wood and some string, the 62-year-old Brit says he and his partner Doug Bower are responsible for confusing the public for over 13 years.

Chorley tells CBC's Michael Enright he has decided to spill the beans because the crop circle phenomenon has gone too far. What started off as a practical joke, says Chorley, has become a million dollar industry spawning a huge tourism industry and a plethora of books. "How do we know you're not fooling us now?" asks Enright. "You don't know, do you?" says Chorley mischievously.

But not everyone is convinced. British crop circle expert Patrick Delgado disputes Chorley's claim. Delgado says there is no way two men can be solely responsible for hundreds of incredibly detailed crop circles. "I don't believe what these men have said is true and they have not brought forward any evidence whatsoever," says Delgado.

• In 2000, a California company began marketing Crop Circle Beer, made exclusively with barley from crop circle fields.

• Colin Andrew, a British electrical engineer who has studied the crop circle phenomenon for 17 years told the CBC's Jim Brown in Aug. 2000, that 20 per cent of crop circles were naturally formed, caused by the earth's magnetic field.

Medium: Radio
Program: As It Happens
Broadcast Date: Sept. 9, 1991
Hosts: Barbara Budd, Michael Enright
Guest(s): David Chorley, Patrick Delgado
Duration: 12:37