Detectives are hunting members of an organised racket who are targeting residents across the region in a money-making scam.

Police believe groups of immigrants from Eastern Europe are being transported to different areas around the North-East and dropped off with the specific aim to con people out of money.

On Monday this week, Cleveland Police received five reports of incidents in Billingham and Saltburn where foreign nationals knocked on doors selling poor quality paintings, or begging for cash.

And the same racket was believed to have been operating in the Peterlee area over the weekend.

Detective Sergeant Greg Swinnerton, of Cleveland Police's Operation Strongbow, which is aimed at catching bogus callers, appealed to residents not to hand over any cash and urged them to report all sightings to police.

"It is clearly an organised racket because of the numbers coming in and because they appear to be getting bussed around from one area to another," said Det Sgt Swinnerton.

"We believe they may be coming in from the Northumbria area. They get dropped off early in the day and then are picked up later on.

"They knock on doors selling poor quality paintings, say they are university students in need of money, and in one of the incidents at the weekend, the caller claimed he needed money for his sick son, who had leukaemia.

"We think there is anything up to half a dozen coming in in a day, both male and female, and while they are never violent or aggressive, witnesses have said they have seen them trying to open front doors."

However, before Christmas, he said a caller was believed to have tried to get in a back door while his accomplice spoke to a homeowner at the front.

Det Sgt Swinnerton said people had admitted handing over cash to the cold callers, but said he believed the gang will have knocked on many more doors than has been reported.

"Our message to people is not to deal with cold callers, to keep doors locked and to use door chains," he said.

"If these people do call, we want to know about it. We need more information to know what we are dealing with, where they are based, and if any offences are being committed."

Anyone who sees the suspicious cold callers, who all speak with foreign accents and are white, or a vehicle dropping off large groups of people, should call Cleveland Police on (01642) 326326.