PEWSEY crop circle researcher and writer Freddie Silva is convinced that most of the current season's patterns and formations are not the work of extra terrestrials or the weather.

His assertion is that the human race is in fact responsible for most of them this year.

However, Mr Silva, whose book on crop circles, Secrets In The Fields, is due to be published in September, said he still believes some of them are formed naturally and could contain messages if their hieroglyphs could be transcribed.

New formations have appeared at North Farm in West Overton, in fields opposite The Bell at Overton, at Bourton near Bishops Cannings and at Stonehenge.

One at West Kennett which looked suspiciously like the Weetabix logo, and which the breakfast cereal makers declined to own up to, now sports the letters WEETABIX.

Mr Silva believes that another crop formation in the shape of a large letter H is the logo for Sky TV's History Channel.

Others, he suspects, have been made for commercial interests, possibly to promote the Mel Gibson crop circle movie which is released in September.

At least one person, Matthew Williams from Bishops Cannings, has admitted making crop circles and was the first person to be successfully prosecuted for making pictograms.

Mr Silva said that as long as hoaxers keep making crop circles and sitting back letting people think they are genuine natural formations, it is difficult for researchers to establish if any are naturally made sorting the wheat from the chaff, as it were.

The writer said: "They are trying to replicate the real phenomenon. They are muddling the issue and, I feel, turning people off a phenomenon which is quite quantifiable."

Of the 25 or so crop formations reported in Wiltshire so far this year, Mr Silva said he believed that no more than four could be claimed to be genuine, naturally formed patterns.

But he said it was possible that a double spiral formation at West Overton and a symmetrical leaf pattern discovered at Stonehenge were the result of a natural phenomenon rather than being man-made.

"Frankly most of them are just a joke and you can even see that from a distance," said Mr Silva.

"If we could rule out the ones made for whatever commercial reasons then we could start seeing what the phenomenon is really all about."

nkerton@newswilts.co.uk