Rogue traders and fraudsters were targeted during a week-long operation.
Operation Rogue Trader involved officers from Sutton police, trading standards, the UK Border Agency and Sutton Council hunting down the con-artists.
The fraudsters target vulnerable people by purporting to be from legitimate companies but then doing sub-standard work or not doing work at all.
During the drive earlier this month officers spoke with more than 300 people in Sutton High Street to find out their concerns and get information on scams.
It led to one arrest and more than £600 in fines being collected.
The drive was part of the national Operation Liberal, an annual campaign.
Detective Inspector David Ball, of operation Liberal, said: "Thanks to the effective partnership between police forces, trading standards teams and other key agencies, Operation Rogue Trader has become a well-established annual campaign focusing on a pattern of offending which deliberately targets the most vulnerable members of our communities, and most often the elderly."
People have been advised not to trust door-to-door callers and to contact companies themselves using the Sutton Safer Trader scheme.
Mary Morrissey, the council's strategic director for environment and neighbourhoods, said: "Operation Rogue Trader is just one of the ways we are ensuring that Sutton remains a safe and fair borough
"People should always be wary of cold callers and use our Sutton Safer Trader scheme which ensures all trades people have undergone stringent background checks"
Visit www.sutton.gov.uk to find out more about the safer trader scheme.
- 'Croydon cat killer' may have claimed 10 more victims in just 10 days
- Shocking figures show how long you'd have to live to afford buying your first south London home
- VIDEO: No laughing matter as two men try to steal gas canisters from St Helier Hospital
- Armed police to travel on the Tube for first time since 7/7
- Fewer mentally ill people being locked up in London police cells, figures show