The enforcement branch of Calcutta police has seized at 25 filled medical oxygen cylinders from an agency in Bhowanipore and at least 15 empty cylinders from a godown in Maniktala.

Officers suspect the empty cylinders were to be used to sell oxygen at a premium at a time the demand for the life-saver has rocketed following a surge in Covid cases.

The police said a racket was operating to procure empty oxygen cylinders from registered sellers and distributors, refill them and sell the gas at double or triple the market rate.

“The raid was conducted based on specific information. We have launched an investigation and sought documents for the empty cylinders found in a godown. If the godown owner fails to produce proper documents, he will be arrested,” an officer of the enforcement branch said.

The empty oxygen cylinders were of different capacities. Thirteen of them weighed 52kg and two 15kg.

Police said the filled cylinders — 10 litres each — were seized because the agency had stored cylinders beyond what it had been allowed to stock.

Sources said multiple teams of the enforcement branch had fanned across the city to look out for illegal sale and stocking of medical oxygen to ensure there was no artificial crisis.

The raids started on Saturday night, within hours of the state health and family welfare department issuing a notification that referred to reports of hoarding of oxygen cylinders across the state.

The notification mentioned that only Covid-19 patients under home isolation or in quarantine and patients of other ailments in need of oxygen could buy or take on rent medical oxygen cylinders from licensed distributors and pharmacies.

Reports of hoarding of oxygen cylinders and life-saving drugs during the Covid-19 crisis are not uncommon in the country.

Reports of deaths of Covid-19 patients in pockets of the country because of lack of oxygen has prompted many to stock oxygen cylinders at home.

Blackmarketeers are stocking cylinders, further intensifying the crisis, to sell them at a higher rate.

A police officer said: “We are trying to prevent hoarding before things go out of control. We request people not to panic. They should buy or take on rent oxygen cylinders only if asked by doctors.”