The Agency is preparing for new legislation

The singer claims 100 acres of land at Ashcombe House, on the Wiltshire/Dorset border, have been inaccurately classified as "open country".

Estate manager, Philip Eddell said: "The impact of having land included as open country would be devastating."

The hearing at the Royal Chase Hotel in Shaftesbury goes on.

The Countryside Agency, which is mapping parts of England to implement a new Rights of Way Act classified the land as "downland".

Under the new law, this gives the public the right to access.

Working estate

The Act states that the public can walk across any land appearing on the final map as open country - mountain, moor, heath or down - or registered common land.

But the pop star and her film director husband, Guy Ritchie, are appealing against the Agency's decision.

Mr Eddell said the celebrity couple had employed him as a management consultant to restore Ashcombe to a working estate with house, pleasure grounds, woodlands, park, farm and shoot, while safeguarding and enhancing the landscape.

He told the inquiry: "It was recognised at the time the estate was purchased in 2001 that parts of the estate may be mapped as open country.

"The publication of the draft maps were a surprise as over a third of the estate had been mapped and there were areas that were obviously incorrect," added Mr Eddell.

The hearing continues.