The National Crime Agency (NCA) has revealed details of a “groundbreaking collaboration” with India’s Central Bureau of Investigation (CBI) and American teams to bust a fraud call centre scam operating from Noida in north India that targeted British victims.

The international investigation began early last year after NCA officers in the US received information from Microsoft, which was compared with City of London Police’s Action Fraud Reports. The NCA and FBI Attaché in Delhi shared intelligence with the CBI, leading to “urgent action” and the arrest of two people.

UK victims alone are believed to have lost over £390,000 in the scam. More than 100 British victims were contacted by frauds offering to fix their computers for a fee, following screen pop-ups suggesting their devices were infected or hacked.

The NCA said: “In reality, the fraudsters were posing as employees of Microsoft, offering software solutions to an attack that had never taken place.”

The criminals used sophisticated tactics to disguise their identity, including spoofed phone numbers and Voice Over Internet Protocol to route calls through multiple servers across several countries. After identifying that the same call centre was targeting US citizens, a partnership was agreed to share intelligence.

Nick Sharp, deputy director of the National Economic Crime Centre, said: “This case demonstrates the success we can have when we harness expertise from across the public and private sectors, and work hand in hand with partners abroad to target fraudsters, wherever they are.”

The collaboration involved 18 months of work between the CBI, NCA, FBI and Microsoft to identify the group, analyse data and target IT infrastructure used by fraudsters.