DETECTIVES have been flooded with calls after The Northern Echo revealed how a North-East father and son disappeared from their horse truck business owing customers money.

The investigation into Just Trucks, run by Gary Upson and his son, Ryan, has been passed from officers in Darlington to Durham Police's fraud squad because of the scale of complaints.

Detectives say the Upsons owe hundreds of thousands of pounds.

And Detective Constable Tim Lerner, from Durham's economic crime unit, said he believed many more victims could have been ripped off by the pair, who converted lorries into customised horse boxes.

The Upsons have not been seen at Just Trucks' premises in Banks Road, Darlington, for more than a fortnight.

Det Con Lerner said he had spoken to about 30 people claiming to be owed cash or vehicles by the Upsons since their disappearance was exclusively revealed in The Northern Echo on June 15.

He said: "I have a feeling that it is just the tip of the iceberg. I think many more will come forward - it's the sort of case where, initially, people may have thought it was a civil matter.

"They may come to the police now they know there is a police investigation."

He added: "We've had lots of people ringing us saying they have lost significant amounts.

"I have spoken to a couple of people who have lost £30,000 and I am told there is a chap who has lost £50,000."

Det Con Lerner asked anyone who has had dealings with Just Trucks to contact police.

"It is one of those cases where the more complaints that come forward, the better," he said.

"If we get a lot more complaints and can demonstrate that the majority of people have been ripped off, that makes a stronger case.

"We also want to interview the Upsons as soon as we can.

"I'm mindful of the fact that, despite the publicity in The Northern Echo, they have still not come forward and told us where they are."

Last night, a picture was emerging of businessmen who could not be trusted.

Freelance tool seller John Hawksby, from Darlington, said they owed him money for equipment he supplied.

"People have been talking for a while about what was going on because of the odd way they behaved," he said.

John Wesson, of Auto Electrics, in Eastmount Road, Darlington, said he was owed money for work on a vehicle.

"We always had to go to get our money and there was always a cock-and-bull story about why they couldn't pay."

Dorothy Bell, from Neasham, near Darlington, had a lorry sprayed by the Upsons for £1,700.

"When we got it back, they'd sprayed over cobwebs, rust and mud. I took them to court and won," she said. "They finally paid me in postage stamps and postal orders."

Customers who bought horse boxes from Just Trucks have told how they battled to get the vehicles delivered.

Ed Parrish, 34, from Eaglescliffe, near Stockton, said it took two years for him to get his vehicle and, even then, it was not finished.

"We paid £8,000 and gave a vehicle in part exchange, but when we demanded our box it was not right and still isn't."

Niel Dae, of Stainton, near Middlesbrough, said: "It took me nine months to get my truck out of them but I finally did. I've been fortunate."

Michelle Thomas, 20, from York, was not so lucky. She took out an £11,000 loan to pay for a horse box that has not been delivered. "I will be paying back the loan for 25 years and I have nothing to show for it," she said.

Anyone with information about Just Trucks or the Upsons' whereabouts is asked to contact the fraud squad on 0191-386 4929