Earlier, Kolkata Police had busted two such call centres which were duping UK residents.
When a user called them, accused persons used to demand money to unfreeze the computer.
On Tuesday night, after conducting the raid, seven persons were arrested from the call centres, who were the masterminds.
"So far, we have arrested seven persons and seized servers, hard disks, pen drives and several incriminating documents.
Earlier, Kolkata Police had busted two fake call centres which were being used to dupe UK and USA citizens.