Alien spacecraft may have been operating over Helston recently - or it could just be the work of local youngsters.

Crop circles - a phenomenon some believe show aliens attempting to communicate with us - are said to have appeared in a field on the edge of the town, according to a resident of the nearby Gwelmeneth housing estate.

The resident, who asked not to be named, said she did not believe in UFOs, but was at a loss to explain the "perfectly formed" circles spotted in the field on Sunday evening.

"I thought it was a hoax but it's too perfect," she said. "There aren't any tracks where people have gone in and the corn isn't broken, which is what happens if it's man made. It's just bent over in a perfect spiral pattern.

"There are outer rings with the corn left standing upright inside them. The lines are really crisp - it's just too perfect to be the work of kids."

The resident reported the phenomenon to the Crop Circle Research Organisation, and also contacted RNAS Culdrose in a bid to secure an aerial shot of the field.

Culdrose spokesman Ian Mackay said crews had been asked to keep an eye out as they were flying over the area and take a photograph if they spotted anything unusual, but no one had reported seeing anything out of the ordinary.

Crop circles - geometric patterns that appear in fields - are believed by some to represent messages from alien spacecraft.

Others have come up with theories of vortexes, lightning, plasma and other less occult explanations involving natural forces such as wind, heat and animals.

The more sceptical believe most, if not all, of the designs are the work of pranksters.

What do you think of the so-called crop circles? Have your say below.