A suspended “insider” was arrested during a pre-dawn swoop on Monday for his alleged role in the Rs 60-crore fraud in the West Bengal State Co-operative Bank (WBCS).

Udayan Majumdar, who was deputy commissioner in the refugee relief and rehabilitation department until his suspension in September last year for some other fraudulent acts, was picked up from his Salt Lake residence. Later in the day, Tridib Das was arrested in the Shyampukur area for his complicity in the crime.

“Majumdar knew the co-operative department inside out and he provided the swindlers with important information,” joint commissioner of police (crime) Pallab Kanti Ghosh said.

Officers investigating the fraud that rocked Bengal’s finance wing meant for the poor said Majumdar’s name cropped up following the arrest of Debabrata Dey and Rajkumar Roy Chowdhury on Sunday. “The two men gave us vital leads that helped us track down Majumdar and Das,” an officer in the detective department said.

He said Das masqueraded as a UCO Bank official. “He gave his account number where the money was deposited. Das diverted the amount to another account and withdrew the money. We are looking for his accomplices.”