NEW DELHI — Within the world’s worst Covid-19 outbreak, few treasures are more coveted than an empty oxygen canister. India’s hospitals desperately need the metal cylinders to store and transport the lifesaving gas as patients across the country gasp for breath.

So a local charity reacted with outrage when one supplier more than doubled the price, to nearly US$200 (S$270) each. The charity called the police, who discovered what could be one of the most brazen, dangerous scams in a country awash with coronavirus-related fraud and black-market profiteering.

The police say the supplier — a business called Varsha Engineering, essentially a scrapyard — had been repainting fire extinguishers and selling them as oxygen canisters. The consequences could be deadly: The less-sturdy fire extinguishers might explode if filled with high-pressure oxygen.

“This guy should be charged with homicide,” said Mr Mukesh Khanna, a volunteer at the charity. “He was playing with lives.” (The owner, now in jail, couldn’t be reached for comment.)

A coronavirus second wave has devastated India’s medical system and undermined confidence in the ability of Prime Minister Narendra Modi’s government to treat its people and quell the disease.

There are widely believed to be far more deaths than the thousands reported each day. Hospitals are full. Drugs, vaccines, oxygen and other supplies are running out.

Pandemic profiteers are filling the gap. Medicine, oxygen and other supplies are brokered online or in hushed phone calls. In many cases, the sellers prey on the desperation and grief of families.

“These people, the cyber criminals, were already out there,” said Dr Muktesh Chander, a special commissioner for the Delhi Police. “The moment they got this opportunity they switched on to this modus operandi.”

Sometimes the goods are fraudulent, and some are potentially harmful.

Last week, police officers in the state of Uttar Pradesh accused one group of stealing used funeral shrouds from bodies and selling them as new. The day before, officers in the same state discovered more than 100 vials of fake remdesivir, an antiviral drug that many doctors in India are prescribing despite questions about its effectiveness.

Citing the predatory sales, a top court in New Delhi said this month that “the moral fabric of the society is dismembered.”

Over the past month, the New Delhi police have arrested more than 210 people on allegations of cheating, hoarding, criminal conspiracy or fraud in connection with Covid-related scams. Similarly, the police in Uttar Pradesh have arrested 160 people.

“I have seen all kinds of predators and all forms of depravity,” said Dr Vikram Singh, a former police chief in Uttar Pradesh, “but this level of predation and depravity I have not seen in the 36 years of my career or in my life.”

The scams and profiteering represent the flip side of the huge online help system that has emerged to fill the void left by the government. Do-gooders across the country have swooped in to connect those in need with lifesaving resources.

The ad hoc system has limits. Vital supplies like oxygen are still stuck in bottlenecks, and people keep dying after hospitals run out. Vaccine and pharmaceutical makers can’t keep up. Politicians in some places are threatening people who publicly plead for supplies.

That empowers the black market, with its exorbitant prices and dicey goods. Many people feel they have no choice.

Mr Rohit Shukla, a graduate student in New Delhi, said that after his grandmother died in late April in a neighbouring state, an ambulance driver demanded US$70 for the three-mile (4.8km) ride from the hospital to the cremation ground, over 10 times the normal price. When the family arrived, workers demanded US$70 for firewood that should have cost US$7.

Supply and demand might account for some price increases, Mr Shukla said, but he suspects more than that.

“Everyone is trying to profit from this pandemic,” he said. “I don’t know what has happened to people.”

Some of the more egregious examples can be found in the country’s struggling hospital system. Infections and deaths are widely believed to be many times more numerous than the official figures indicate, and in hospitals across India, all the beds have been filled and people are dying for lack of oxygen or medicine.

Accusations by one doctor in Madhya Pradesh have gone viral. The doctor Sanjeev Kumrawat said he tried to stop a local activist for India’s governing party from selling access to beds in a government hospital where he works.

“We all know that to get a bed is a big struggle all around,” Dr Kumrawat said in an interview. “Government resources are to be distributed equitably and can’t become the property of one person.”

The activist, named Mr Abhay Vishwakarma, disputed the accusations but said he had asked the local authorities to investigate. “I don’t know why the doctor has accused me,” he said in an interview.

A brisk market has developed for contraband plasma, which many doctors in India have used to treat Covid-19 patients.

Police officers in the city of Noida, in Uttar Pradesh, on Wednesday arrested two men they accused of selling plasma for up to US$1,000 per unit. According to the police, one of the men begged for plasma donors for his own needs on social media, then sold the plasma through a middleman.

Young cybersleuths are trying to help by cruising social media sites to find scammers.

Ms Helly Malviya, a university student, flagged a Twitter post advertising a drug, tocilizumab, an anti-inflammatory drug sometimes used to treat Covid-19 patients with pneumonia that is hard to find in India.

The seller wanted US$2,000 in advance. Ms Malviya flagged the post as a possible scam and received a flurry of messages, but they were from people desperate for the drug.

“This is the kind of helplessness people are facing these days,” she said.

Remdesivir, the antiviral drug, has been the focus of a number of scams.

The police in New Delhi recently said they had arrested four people working at medical facilities who swiped unused vials of remdesivir from dead patients and sold them for about US$400 each. Before the drug became so scarce in India, hospitals were charging about US$65 for it.

The Surin family, from the city of Lucknow, recently paid more than US$1,400 to a middleman for six doses of remdesivir. Ms Lucky Surin, an event manager, said the family had little choice. Her mother and sister-in-law were seriously sick. Her mother has since died.

“What do we do?” asked Ms Surin. “If the doctor has prescribed it, then you have to buy it.”

Dr Jawed Khan, owner of the hospital that prescribed the drug for the Surins but couldn’t provide it, said families could procure their own and physicians would check vials and labels for authenticity.

Some scammers try to get around such safeguards. The police in the western state of Gujarat this month discovered thousands of vials of fake remdesivir during a bust. A tipster led them to a factory where they recovered 3,371 vials that were filled with glucose, water and salt.

Many other doses had already been sold and maybe even put into patients’ bodies, the Gujarat police said, posing a public health risk of unknown scale.

Those who turn to the black market often know they are taking a gamble.

Mr Anirudh Singh Rathore, a 59-year-old cloth trader in New Delhi, was desperately seeking remdesivir for his ill wife, Sadhna. He acquired two vials at the government-mandated price of about US$70 each. He needed four more.

Through social media, he found a seller willing to part with four more vials for about five times that price. First, two arrived. When the second two were delivered, he noticed the packaging was different from the first batch. They had been made by different companies, the seller explained.

The Rathores had their doubts, but Sadhna’s oxygen levels were dropping and they were desperate. Mr Singh Rathore said they gave the doses to the doctors, who injected them without being able to determine whether they were real or fake. On May 3, Sadhna Rathore died.

Mr Singh Rathore filed a police report and one of the sellers was arrested, he said, but he has been wracked with guilt.

“I have the regret that probably my wife would have been saved if those injections were original,” he said, adding that the police had sent the vials to be tested.

“People are using the crisis period for their own benefit,” Mr Singh Rathore said. “This is a moral crisis.” THE NEW YORK TIMES