A nature expert has destroyed acres of Hampshire's valuable downland in a bid to stop walkers being given the right to roam across his property.

Zoologist, Dr Nigel Potter, sacrificed 18 acres of prime chalk grassland at his farm near King's Somborne just to beat new public access laws.

His actions have sparked outcry from environment bosses, who this week condemned it as a "tragedy" for Hampshire's countryside.

But an unrepentent Dr Potter is now threatening to plough up the rest of the downland, which is rich in wildlife, at his 1,350-acre Forest of Bere Farm, at Ashley.

He is angry that the Government's controversial Countryside and Rights of Way (CROW) Act is to allow walkers access to open country- even if it is privately owned.

Dr Potter, who claimed still to be a "great conservationist", told the Hampshire Chronicle: "I did not want the public wandering along my land and my pheasant drive, or the handicaps of public access 24 hours a day.

"I might have coped with 12 hours, but not with 24. It's private property. I do not see it as being any different from No 10 Downing Street's garden."

For the past 10 years, Dr Potter has been receiving government cash for converting the former arable site back to chalk downland.

But once the agreement came to an end, he decided to plough it up and resow it with crops- a week before tighter restrictions on farmers using such land for intensive farming came into place.

Now he hopes to exploit a legal loophole to keep people off the rest of his property.

"Part of the reason I ploughed the downland up is because the Crow Act says a parcel of land that is less than 50 per cent does not qualify.

"What I did reduces my downland to less than 50%. If that does not work, then I will plough it up," he warned.

Countryside expert for Hampshire County Council, Merrick Denton-Thompson, condemned Dr Potter's actions, but said the Government was not offering landowners the necessary support to entice them to go along with the new right to roam rules.

Mr Denton-Thompson said: "It's a real loss for Hampshire and for the public's enjoyment of the countryside, as well as making more vulnerable the sites that remain.

"The legislation has not been well thought out and you can sympathise with land owners. There's got to be the right incentives for them to deliver society's aspirations."

A spokesman for the Department of Rural Affairs confirmed that its officers were aware of what had been done and that they had visited the farm.

But, as no regulations had been broken, they were no longer investigating the incident.

John Archer, technical advisor to the Hampshire branch of the National Farmers' Union, said its members were advised not to plough up their land to avoid the new laws.

"You might get the odd renegade who might do it for the sake of it, but I really do not think people would go to those lengths to prevent public access."

Don Anderson, access officer for Hampshire Ramblers, described Dr Potter's actions as "deplorable".

Last year, national outcry was caused by farmers in the Peak District ploughing their land to avoid the new laws.