A pilot was forced to land his new £50,000 four-seater aircraft on a hill in thick mist.

He walked away from the plane uninjured, leaving the keys in the cockpit.

The Regent aircraft got into difficulties near Shoreham airport and landed on Southwick Hill, above the Brighton bypass tunnel.

The pilot had aimed to land at the airport at lunchtime but decided not to take the risk.

He told air traffic control he was about two miles north-east of the airport and because of bad visibility it would be safer to land on a flat area of the Downs rather than the runway.

Worried residents phoned 999 to say the plane had come down but police had difficulty finding the exact spot.

The Sussex Police helicopter made a sweep of the area but was unable to find it because of the weather.

The plane's pilot managed to alert the control tower at Shoreham to say he was not injured.

An airport spokeswoman said: "The pilot told us visibility was so bad he felt it was not safe to try to land at Shoreham.

"He said he was going to land in a field, which was two miles north-east of the airport.

"He obviously left the plane in the hope of flying again when weather conditions improved."

Eddie Mitchell, a photographer with The Argus, found the plane with police officers.

He said: "We could not believe it when we discovered he had walked away, leaving the keys."