The Enforcement Directorate (ED) on Thursday arrested Kolkata Police Deputy Commissioner Santanu Sinha Biswas in connection with a fraud and extortion case, officials said.
Biswas was arrested after over 10 hours of questioning at the agency's office in the city, they said.
"Santanu Sinha Biswas was questioned in connection with the ongoing probe into alleged land grabbing, extortion and financial irregularities linked to the Sona Pappu network. He repeatedly avoided giving direct replies and did not cooperate with the investigation," a senior ED official said.
"Based on the material collected and his conduct during questioning, he was placed under arrest," he added.
Biswas, who is currently posted in the Security Control division of Kolkata Police, appeared before the agency after skipping multiple summons, citing official engagements.
A lookout circular had also been issued against him by the agency.
Investigators are probing his alleged links with businessman Joy Kamdar, considered close to Sona Pappu, in connection with the fraud case, officials said.
Several WhatsApp chats recovered during the investigation were also placed before Biswas during questioning, they said.
A former officer in charge of the Kalighat police station, Biswas, has been under the scanner in multiple cases. Investigators suspect he had links with Sona Pappu, a criminal allegedly involved in land grabbing, extortion and other offences in the Kasba area of the city, they added.
The ED is also examining his alleged role in cases related to illegal sand trafficking and a previous arms recovery linked to Sona Pappu's premises, officials said.
ED officials had conducted searches at Biswas' residence on Fern Road in Ballygunge ahead of the elections.
A day after the searches, the agency had summoned Biswas' two sons, Sayantan and Manish, to the CGO Complex office, though neither appeared before the investigators.
"Despite repeated opportunities, he failed to join the investigation meaningfully. Further custodial interrogation is required to ascertain the larger conspiracy and financial trail," the official said.
Biswas is expected to be produced before a special court on Friday after completion of formalities, he added.