Sniffer dogs and search-and-rescue teams linked up last night in a bid to find missing pensioner Peter Butter-field.

More than 20 police officers and volunteers from Calder Valley Search and Rescue Team, with specially-trained dogs, combed woodland around the Hawksworth and Hollins Hill areas in an intensive hunt for the former soldier.

He was not found, but police were today investigating another reported sighting of the pensioner.

Mr Butterfield, 72, who suffers from depression, vanished from the home he shared with wife Betty in Roydswick Terrace, Cullingworth, on Saturday, May 10, while Mrs Butterfield was out shopping.

There have been previous two sightings of Mr Butterfield - at Roundhill, near Baildon, where he was seen by a woman, and a week later on the first fairway at Hollins Hall golf course.

But concern for his welfare has mounted since, leading to last night's major search which was called off at midnight.

Mr Butterfield, who has gone missing twice before, left his medication behind and it is thought he will be in an agitated state because he has not been taking it.

But police revealed that he had learned basic survival training during the 1950s while he was in the army in Malaysia, which he used while he lived rough for three weeks the last time he disappeared five years ago.

It is believed Mr Butterfield, who is thought to have vanished because of an imminent appointment with a psychiatrist, had originally been living in a tent which is missing from his home.

But police believe he will now be sleeping in a more secure shelter which he returns to at night-time.

Chief Inspector Steve Hobson, of Keighley Police, said: "He is probably staying in a workman's hut, a disused shed or a toilet on a quarry site, which he returns to at night.

"That is why we are making this search during the evening."

The search team was concentrating on woodland around Hollins Hill and Hawksworth - areas where Mr Butter-field was brought up and where he was found on a previous occasion.

But Chief Insp Hobson admitted fears were growing for the pensioner.

"My heart says that we will find him alive but as the days go by our concerns grow," he said. "You have to keep your hopes up and we are still hopeful, but we are worried for his welfare.

"I have become close to his wife Betty and she is holding up very well considering what she is going through.

"This has become a bit of a personal goal for me and I will be happy when we find him safe."

Chief Insp Hobson said the survival skills Mr Butterfield had learned in the army had been enough to keep him alive the last time he went missing and he hoped they would be sufficient again.

He added: "He will have found a shelter. He will move through the day and return to his shelter at night. That is why we were searching last night."

He said Mr Butterfield could have a knife with him and up to £2,000 in cash.

He had bought food at local shops on past disappearances and enjoyed fish and chips. The last time he vanished he had two receipts for Harry Ramsden's fish restaurant with him.

Chief Insp Hobson said that despite the major searches it was likely that the pensioner would be found by a member of the public, as he was last time.

Mr Butterfield is white, 6ft tall and with short grey hair. When he went missing he was wearing a green wax jacket, two cardigans - one dark, one grey - beige trousers, black Doctor Marten boots and a silver Seiko watch.

Anyone with information is asked to contact Keighley Police on (01535) 617059.