SERIOUS damage by off-road vehicles to the Fosse Way at Easton Grey near Malmesbury is threatening to destroy some of the most important Roman remains in Wiltshire.

Four-wheel drive vehicles are churning up ruts three-feet deep as they drive on the path and through parts of the River Avon for sport.

Their actions have appalled English Heritage and local people who fear the vehicles will destroy the remains of a 2,000 year-old Roman settlement buried beneath the Fosse Way.

Parts of a town dating between the second and fourth centuries AD are still visible in nearby fields and the area also includes a medieval moated site in adjacent woodland, one of the few to survive in southern England.

English Heritage, which will be excavating the site over the next few months to assess the condition of the remains, is now teaming up with Wiltshire County Council, Wiltshire Police, and the Environment Agency in a bid to stop damage to the site.

Archaeologist Roy Canham of Wiltshire County Council said: "The archaeology is very valuable and sensitive. The Roman remains are just six to nine inches below the surface.

"The low-lying part of the town and the Fosse Way are damp areas adjacent to the stream and are easily damaged by vehicles."

In 2001, the county council spent £7,500 to repair previous damage to the riverbed of the Avon caused by the off-roaders. The site was closed to traffic by law in 2002 and dragons' teeth two-foot concrete bollards were installed by Wiltshire County Council, but have since been destroyed by the off-roaders.

Part of the area near Easton Grey bridge is also protected as a Scheduled Ancient Monument.

But despite costly efforts by Wiltshire County Council and English Heritage, the drivers continue to cause damage. Inspector of Ancient Monuments at English Heritage, Phil McMahon, said: "A hardcore of four-wheel drivers persist in tearing up the barriers. They don't seem to care about the massive damage they are causing."

Drivers also threaten wildlife including a rare and protected species of native white-clawed crayfish that was reintroduced to the Avon by the Environment Agency after being wiped out by disease in the 1980s.

The vehicles stir up silt, which clogs the crayfishes' gills and destroys the riverbank where they make their burrows.

Chairman of North Somerset Land Rover Club, Steve Goodfellow, said the club had stopped using the Fosse Way since November and there was plenty of other areas where drivers could drive safely. He said: "It is possible that the drivers using the Fosse Way are rather inexperienced and do not know the damage they can do."

Sergeant Gavin Williams of Malmesbury Police appealed to the public to look out for the vehicles, note their licence number and contact the police.

He said: "Drivers could be causing criminal damage to the land and river. We need witnesses." Call Malmesbury Police on (01666) 822222.