Trading standards officers are trying to track down an unusually large and sophisticated group of rogue builders operating in south Cumbria.
Officials say the group has charged hundreds of pounds for small jobs shoddily completed, and given false addresses.
It is using two or three nearly new yellow vans, each with two young men on board.
Pat Thomas, from trading standards, said new legislation was needed to deal with rogue builders.
'Easy' solution
In the meantime, officers have said they will do what they can to stop the men operating in the area and have warned people to be on their guard.
Mr Thomas said: "The easiest solution is to chase them out of town.
"We will endeavour to see if they have committed criminal offences, in which case we will pursue them.
"But of course chasing them out of town just throws them into Lancashire, or Cheshire, or Yorkshire, and in many ways.
"In many ways that is just passing the problem over."