The man, Baruch Feldheim, 43, was charged with making false statements to law enforcement officers after he lied about stockpiling and selling equipment that is desperately needed by hospitals as they confront a surge in virus patients, the authorities said.

Mr. Feldheim repeatedly sold the equipment at a markup, according to a criminal complaint filed against him in Federal District Court in Newark.

On one occasion, in a transaction arranged via a WhatsApp group named “Virus2020!,” Mr. Feldheim agreed to sell a doctor about 1,000 N95 masks and other gear for $12,000, according to the complaint. That was about 700 percent above what the doctor, who was not identified, would typically pay, the complaint says.

When he met with Mr. Feldheim at an auto repair shop in Irvington, N.J., on March 18, the doctor saw enough including hand sanitizer, Clorox wipes and medical supplies to “outfit an entire hospital,” the complaint says.

F.B.I. agents went to Mr. Feldheim’s home on Sunday to get more information, the complaint says. At that point, the complaint says, he “intentionally coughed in their direction without covering his mouth,” even though the agents had said they were keeping their distance out of concern over the virus. He told the agents that he had tested positive for the virus two weeks earlier, the complaint says.

Last week, a top Justice Department official warned federal prosecutors to be on the lookout for threats to spread the virus, and said that such acts could potentially be prosecuted under federal terrorism laws because the virus was considered a “biological agent.”

Mr. Feldheim was not charged under federal terrorism laws. A spokesman for the United States Attorney’s office in Newark declined to comment on whether he might be.