Detectives have charged seven people over allegations they conned elderly people in Essex out of around £1 million.
Essex Police said there were around 40 victims aged between 65 and 99.
Sixteen people were arrested in Colchester, Clacton and Epping yesterday.
Seven have been charged with conspiracy to commit fraud by false representation between 2009 and 2013. The charges relate to work carried out on victims' homes at inflated prices.
Six men will appear at Colchester Magistrates' Court later today. A woman has been bailed to appear in court on July 16.
The remaining nine people have been released on bail until next Wednesday.
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