ROCKFORD, Mich. — Two businesses in Rockford are accused of marketing a “coronavirus defender patch” and falsely claiming it protects people from the virus.

The Michigan Attorney General’s Office sent a cease and desist letter to Frequency Apps Corp. and Biores Technologies, Inc. Authorities say the companies claim the patch will help a user’s immune system defend against exposure to the virus and lessen the effect for people who already have it.

The patch was priced at $49.99 and the companies offered a free 30-day supply when people bought a 45-day supply.

“Providing consumers with a false sense of security that these patches could somehow protect them from the virus is simply wrong,” Attorney General Dana Nessel. “I will not tolerate deceptive and misleading business practices at any time, but especially not during this time of uncertainty surrounding Michigan’s battle with COVID-19.”

Both companies have 10 days to respond to the letter and agree to not market or sell the patches, and to provide contact information for everyone who purchased them.

Citizens can file a price-gouging or scam complaint by calling the Consumer Protection tip line at 877-765-8388.