Sex workers have been calling with important information for a team trying to break the sex-trafficking trade in Cambridgeshire, police have revealed.
The workers have told police working on Operation Radium that they want to help young girls being forced into working as prostitutes by criminal gangs.
The information is needed for police to locate brothels in the county.
They hope to find out who is behind the trafficking of young girls from Eastern Europe, Africa and the Far East.
"The women who have been in touch with us see and hear things other people wouldn't," said Det Ch Insp Paul Fullwood who is leading the operation.
"Their information as 'insiders' is very important to the intelligence-gathering and preparation side of Operation Radium," he added.
Operation Radium is part of a national drive against sex trafficking.
It was launched in Cambridgeshire on 7 August, and police say they are grateful for the response they have had from members of the public as well as sex workers.
Last week police opened the Operation Radium files to highlight the extent of the victims' suffering.