Police in Oxfordshire are using a law that is more than 130 years old to clamp down on rogue traders.
The crackdown targets the "well established" links between bogus traders and distraction burglaries, police said.
Using the Pedlar's Act, officers do not need to establish a suspect's intent to steal but can ask for them to produce a trading certificate.
If they cannot they can be charged with an offence under the Pedlar's Act.
They have asked people living between Banbury and Chipping Norton to report people making unsolicited calls.
Pc Matthew Leaney, who has been seconded from Thames Valley Police for a year, said police and trading standards officers were sharing intelligence and over the last month since the operation started they had already gathered a list of people to investigate.
"The trading standards don't have power to arrest people, which makes it quite hard for them to deal sometimes with out-and-out con artists," he said.
However, Det Con Lee Newman said that police can use the Pedlar's Act to deal with people who are operating without a certificate or who refuse to produce a certificate when requested by an officer.