The city police have received at least eight complaints on online frauds related to the supply of oxygen cylinders in and around Calcutta in the past 24 hours.

In all the cases, the complainants had transferred the money online to different bank accounts but had not received any oxygen cylinder in return. The police have tracked these accounts to places in Bihar and in South and North-24 Parganas.

The city police had on Thursday published a helpline number (9874909640) and the e-mail ID of joint commissioner (crime) — jtcpcrime@kolkatapolice.gov.in — to report frauds related to the pandemic.

In some of these cases, people were duped with double or triple the rate of an oxygen cylinder as they had made an online payment without realising that they would never get the service.

The police said fraudsters were choosing their targets from social media, who were posting their urgent needs of life saving drugs or a hospital bed or oxygen. “People who are posting their urgent requirements on social media are most vulnerable. It is easy to dupe them...,” said an officer.

Although eight cases were reported within a day of publishing the helpline, a section of the police believes that the actual number is higher than what has surfaced. “Many people are too busy saving the life of their near and dear ones to report anything to the police,” said an officer in Lalbazar.

A senior police officer said it was always advisable to verify any lead before sharing the information or transferring money for any service.

“...We are trying to identify the fraudsters through the money trail.”

Social media is flooded with unverified leads sharing purported information about phone numbers for supply of oxygen, life-saving drugs used in Covid treatment, plasma and for arranging beds in hospitals.