MATTHEW Williams's attempt to debunk the theory that crop circles are anything but human in origin landed him in court this week.

The first-ever prosecution for making crop circles has uncovered a vicious rivalry between the different factions in crop circle investigation, with allegations of harassment, dirty tricks and even threats of physical violence.

Williams, of Bourton Lane, Bishops Cannings, left Devizes Magistrates' Court on Monday with a fine of £100 with £40 costs after pleading guilty to one charge of criminal damage.

He and a friend, now back home in the United States, created the seven-pointed star in a field at West Overton in August to prove to another local expert, Professor Michael Glickman, that even a design as complex as that could be achieved by two ordinary men with nothing more high-tech than some poles, planks and rope.

But Prof Glickman remained unimpressed. Speaking from his home in Horton on Monday, he said: "To suggest Williams did this in response to anything I said is ridiculous. He and his friends do this kind of thing regularly. I said seven-point geometry was hard for humans to do but I didn't say it was impossible."

Prof Glickman, a multiple sclerosis sufferer, said he spends 365 days a year studying crop circles, has been doing it for 10 years and can tell a 'hoax' circle from a 'genuine' one.

Although he does not say that crop circles are created by extraterrestrial intelligence, he says he is willing to keep an open mind and the hoaxers are 'muddying the waters'.

He added: "These unemployed jerks are just looking for excitement and notoriety. They're like small naughty boys who just want attention."

Williams, speaking at his home in Bishops Cannings on Tuesday, said he and his colleagues didn't consider themselves as hoaxers. He said: "If everyone stopped making crop circles, there wouldn't be any. One day the truth will come out and everyone will see how Michael Glickman has been hoodwinking the public."

The feud between the investigators and the debunkers has gone beyond insult and invective. Williams has accused Prof Glickman of threatening to attack him and his supporters with baseball bats.

Prof Glickman denied that and alleged Williams had said next year they were 'going to take out' both him and Francine Blake, of the Wiltshire Crop Circle Study Group.

"And I don't think he meant take us out to dinner," he added.

Williams replied: "We may have used that language but Glickman knows full well what we meant and it wasn't anything violent."

He added: "I came down here believing crop circles were not man-made but I changed my mind."

Michael Maude, the farmer who owns the field in which the seven-pointed star appeared, was not prepared to comment on the case.

Williams received support from an unexpected source in Mike Pitts, the Avebury-based archaeologist.

He said: "I think what he's done is brilliant. I don't condone the damage to the crops but the whole crop circle thing has been taken over by lunatics and people out to exploit a gullible public for their own ends."

In court, Williams told the bench he was unemployed and lived on £51 a week benefit. Though he had appeared on BBC TV's Country File, he had received no remuneration for it.

He said although he had been retained by a company to create their logo in a field of crops for an advertising campaign, it was a one-off engagement and he had received only expenses for it.

After the hearing, Williams was driven away without speaking to waiting journalists.