One person was arrested with heroin worth over Rs 20 crore from the Kolkata's Esplanade area, police said on Saturday.
The person was later identified as a Malda-based drug peddler, the police said.
Acting on a tip-off, officers from the narcotics department of Kolkata Police's Special Task Force (STF) held the accused on Friday evening and seized heroin weighing 3.75 kg from his possession, a senior police officer said.
"The cost of the seized drug is over Rs 20 crore in the international grey market. Further investigation is underway," he added.