Disappearance of Paralowie man Kenneth Camplin declared major crime by South Australia Police

THE disappearance of Paralowie man Kenneth Camplin - last seen on his veranda on Boxing Day -has been declared a major crime.

MISSING Paralowie man Kenneth Camplin left his dog without food and water and the back door of his home open before vanishing without a trace.

Mr Camplin, known usually as Kenny, disappeared some time after waving to two unidentified men outside his Elder Crt home at 11am on Boxing Day.

The mystery men were described as thin with dark hair and aged in their 20s.

Four days later, his brother and a friend found "Kenny's'' back door open and his "beloved'' border collie-cross pet dog starving and thirsty.

The dog is now being cared for by friends.

Emotional friend Rob Gibbs, who has known Kenny since their school days, said in a videoed interview that leaving the dog starving and the house unlocked was "totally out of character''.

"It's not like Kenny to leave his dog and not answer his phone,'' Mr Gibbs said. "He's got a lot of friends worrying about him.''

Mr Camplin, 44, was close to his mother and several brothers.

Major Crime Detective Inspector Greg Hutchins said police had grounds to suspect he had met with foul play.

Police particularly want to speak to the men seen leaving Mr Camplin's home on December 26.

"(The) investigation has uncovered a few things which lead us to believe he has been the victim of foul play,'' Det-Insp Hutchins said.

"Mr Camplin was waving 'goodbye' to those males and everything seemed very amicable but we have not been able to identify who those males are.''

Det-Insp Hutchins would not release the details that led police to declare the case a major crime but said the unemployed Mr Camplin had no known history of drug taking or debts and no serious criminal convictions.

He also did not have any health issues to indicate he had depression.

Police said their concern for Mr Camplin was heightened because he was "very security minded and doted on his dog".

"He always locked his home and would never leave his dog to suffer,'' Det-Insp Hutchins said.

Elizabeth police say they have conducted extensive investigations - including accessing Mr Camplin's bank and telephone records - without turning up a trace of his whereabouts.

"We are really concerned about this missing person (because) no one has heard anything, and I mean anything, from him at all,'' Detective Chief Inspector Krystina Koza said at the weekend.

"He would normally let people know (where he was going) and we would have an idea of where he's gone but we have absolutely nothing.''

Chief-Insp Koza said Mr Camplin usually stayed near his home and kept to himself.

"We're just very, very concerned that this guy has gone missing," she said.

"Police have done extensive inquiries at places where he has visited or gone to in the past and we have got absolutely ... no sightings or communications from him since the 26th.

"He'd go camping but we have explored all of those (locations) and found nothing at all.

"We've gone through everything with a fine-tooth comb.''

Mr Camplin is 175cm tall and weighs 120kg with blue eyes, fair complexion, shoulder- length brown, wavy hair and is usually unshaven.

Anyone with information should call CrimeStoppers on 1800 333 000.