POLICE have intensified their search for an elderly man who went missing on Marley Common on Sunday evening.

Eric Mitchell,who suffers from senile dementia, was believed to have wandered off from the Rosemary Park Nursing Home in Marley Heights, on the West Sussex and Surrey borders.

A massive police search involved more than 70 officers, trained search teams, dog units, off-road motorbikes, an underwater search team and police horses. They combed the wooded area and thick undergrowth surrounding the home, close to Camelsdale and Lynchmere. Police set up a base at the home and have focused their operation on the immediate area surrounding the home.

On Wednesday, the police said they were becoming "extremely concerned" for Mr Mitchell's welfare, but as The Herald went to press, he still had not been found.

Mr Mitchell, who will be 80 this year, moved into the home for mentally disabled people last month from another nursing home in Petworth.

Staff at the home realised he was missing around 8-15 pm on Sunday. It is believed he may have climbed out of a window. After a search of the immediate area by staff in their cars, the police were called in. It is feared that Mr Mitchell walked off towards the common.

A Surrey police helicopter circled the area into the early hours of Monday using searchlights and thermal imaging in the hope of finding the confused man. By Monday morning the Sussex police helicopter had joined in the search.

Mr Mitchell is described as 5ft 7ins tall and with grey hair. He is said to look younger than his years and may appear to walk with a stagger.

He left the home without his glasses and was not wearing his top set of dentures. He was dressed in a mid-blue shirt, grey trousers and brown shoes.

It is the second time that Mr Mitchell has gone missing from the home. Soon after moving into Rosemary Park he wandered off and was found one-and-half miles away in Hammer a short time later.

Because of the difficult terrain, police are not asking for volunteers to help in the search. Boards have been placed around the area asking dog walkers and other road users to report any sightings to the police

Police are also appealing for local residents to check their gardens and outbuildings, such as garages and sheds, in case Mr Mitchell has tried to find shelter overnight.

Farmers and gamekeepers have been asked to check buildings and grounds.

Inspector Tony O'Donnell, from Sussex police, confirmed that a number of sightings have been reported to the police so far, including one on Monday morning close to the Sussex border in Lynchmere, which was investigated by a dog unit.

Some of the sightings have come from as far as the M25, but none has been positively confirmed.

"We've had a number of possible sightings of him in the immediate vicinity, but nothing positive," Insp O'Donnell said on Wednesday.

"We are doing a line search of areas near here and are continuing to search while it's daylight."

He said they were searching particular areas that the experts have identified.

"We also have patrols of officers during the hours of darkness and Surrey Police are aware and looking out as well."

Chief Inspector Andy Buchan added: "As the days go on, the likelihood of finding Eric Mitchell safe and well lessens but we are still keeping an open mind and continuing to ask members of the public to keep their eyes open and report any possible sightings."

Mr Mitchell's family, from the Petworth area, have been kept informed of the police operation and have visited the nursing home and spoken to policemen controlling the search.

They have also been helping the police to review closed circuit television tapes.

On Wednesday evening Inspector Tony O'Donnell said police had completed their search of the immediate area as best they could, taking into account the difficult accessibility of certain areas on Marley Common.

"We will continue our investigations, appealing for witnesses and sightings of Mr Mitchell and checking CCTV footage, in the hope that someone can help."

If Mr Mitchell was still missing by the weekend, a week after his disappearance, Mr O'Donnell said the police would set up road blocks and speak to drivers, as part of their ongoing investigations.

Anyone with any information or who sees a person fitting Mr Mitchell's description should contact Sussex police on 0845 60 70 999.