The city hosts numerous parties and events during Christmas and New Year revelries and drug peddlers throng the hotspots to cater to the demands of party-hoppers, sleuths from the Narcotic Control Bureau said.
"It is only recently that Kolkata is emerging as one of the top cities in India where banned drugs like hashish, LSD are sold during this time of the year.
"The demand for drugs rises in this period and several peddlers are seen flocking the city to sell these narcotics," Dilip Kumar Srivastava, Zonal Director, Narcotics Control Bureau Kolkata, told PTI.
According to him, drugs are reaching Kolkata through various routes.
"Hashish which is also known as Malala charas is quite popular here because it is not that costly. While Hashish is coming mainly from Himachal Pradesh, drugs like LSD are supplied from Europe, the US and China," Srivastava said.
Drug peddlers hand over consignments to middlemen, who then strikes a deal with buyers, he said.
College students are also roped in to sell drugs, the NCB zonal director said.
"In some cases, peddlers use students to route drugs to the customers. Several students are also directly involved in selling the drugs to the purchasers," Srivastava said.
Besides popular pubs, there are several bars in the city where drug peddlers have made a safe den for their business, another NCB official said.
Incidentally, the NBC in Kolkata had arrested five persons, including a management student and a DJ with a popular pub in the city, earlier this month for their alleged involvement in a drug racket.
Around six to seven top schools in the city have been asked to set up a mechanism by the NCB to keep a tab on students as drug smugglers often target vulnerable teenagers, Srivastava said.
Asked about the ways and means people use to contact the peddlers, the zonal director said social media and chatting apps are used for the purpose.
Facebook, Whatsapp and other communicating sites are often used to contact the drug sellers and probable buyers, he explained.
If you wish to procure it, you will manage anyway, he said.
The NCB will be on the lookout for drug peddlers in the city this year and has alerted the Excise and the Kolkata Police in this connection.
Last week, the Excise department with the help of the NCB had arrested two women from the city and seized consignments of Hashish from them.
On enquiring about the actions initiated against drug peddlers, a senior officer of Kolkata Police said that necessary precautions have been taken to deal with this menace.
It is not that drugs are being supplied only to the rich. It is reaching anyone who can manage to buy it. So you cannot actually say that drug peddlers are targeting a specific class of the society," the police officer said.
There are risks involved in the operations and caution needs to be exercised while dealing with this sensitive issue, another senior officer of Kolkata Police said.
We are well prepared and our officers are keeping a watch on possible people who could be involved in this racket, he said.