A man, allegedly involved in activating SIM cards using the credentials of unsuspecting customers, and a dealer, who would sell those SIM cards, were arrested on Monday.

Suvendu Gayen, 30, a resident of Picnic Garden Road, was arrested at his office-cum shop in Tiljala. Over 1,200 SIM cards, a fingerprint scanner, three mobile phones and around ₹2 lakh in cash were seized from his office.

Gayen later informed the police about the person who collected the SIM cards and sold them.

Jitendra Agarwal, 43, was arrested around Monday midnight. The police suspect the two are part of a bigger racket.

Eight people were arrested earlier, following a series of raids on February 24 and 25. Investigators learned about Gayen while interrogating the eight.

“Gayen is a point of sales (POS) operator based out of Kustia Road in Tiljala. It appears that he used to collect data of unsuspecting customers using a fingerprint scanner and used the data to activate SIM cards,” said a senior police officer.

A person purchasing a SIM card had to give his fingerprint impression on a biometric authentication device. The purchaser is asked to press down on a fingerprint scanner so its digital impression can be recorded.

The police said fraudsters use a thin layer of a glue-like substance on the device to emboss the physical imprint of the finger.

“If someone presses the scanner once again, keeping the glue-like substance intact, the person’s fingerprint that was embossed earlier will be reflected again. Multiple SIM cards can then be issued using the fingerprint,” said a police officer.