A Detroit doctor has been charged with health-care fraud after allegedly selling vitamin C infusions that he claimed would protect patients from the novel coronavirus, federal prosecutors said Tuesday.

Dr. Charles Mok, a 56-year-old owner of Allure Medical Spa, was charged on Friday with health-care fraud and conspiracy to commit health-care fraud after allegedly submitting false Medicare claims for “medically unnecessary services,” including “high-dose intravenous vitamin C infusions to patients at risk of contracting COVID-19” and those who had already tested positive, according to a criminal complaint by the U.S. Attorney’s Office for the Eastern District of Michigan.

The U.S. Food and Drug Administration has not approved any drugs to treat the virus.

“Dr. Mok is charged with exploiting the current pandemic to defraud the Medicare program and putting the safety and health of his patients at risk in doing so,” U.S. Attorney Matthew Schneider said in a statement. “These are serious allegations, and my office is committed to prosecuting any medical professional who attempts to use the COVID-19 crisis to defraud patients or insurers.”

The charges come days after federal law enforcement and members of the Department Health and Human Services raided one of Allure’s 26 outpatient facilities on allegations the clinic was involved in fraudulent activity.

According to a 47-page criminal complaint unsealed on Tuesday, Mok allegedly submitted fraudulent claims to Medicare between January and April for treatments of varicose veins—a treatment that his clinics in eight states specialize in.

Prosecutors allege that, through vague note-keeping and false claims, Allure was submitting claims for millions of dollars in services that were “medically unnecessary.” Mok continued these schemes and remained open as a vein treatment center even after Michigan issued a stay-at-home order on March 20 that mandated they close.

While his competitors closed their doors to curtail the spread of the virus, Mok allegedly “responded by saying the other practices were ‘cowards’ and the COVID-19 pandemic is an ‘opportunity to capture the market,’” the complaint states.

Mok assured staff that Allure could remain open with strict safety guidelines. However, one cooperating witness, who is an employee, told authorities that five employees who tested positive for COVID-19 continued to work and treat patients, according to the complaint.

At least one of them was assigned by Mok to treat COVID-19 patients because that employee “had already contracted the virus.”

The complaint states that on April 12, the medical spa began offering high-dose intravenous Vitamin C therapy for patients at risk of contracting the virus—which included essential workers and those on the medical frontlines—or those who had already tested positive.

Mok also marketed the procedure in several videos, stating “hospitals across the county” were using Vitamin C “to treat the most advanced COVID-19 related disease for individuals who tested positive.”

“It is also being used to reduce the duration and severity of illness in more moderate forms of COVID-19...it is becoming standard of care to use high-dose Vitamin C for the sickest people,” the doctor said in one video, according to the complaint. In another video, Mok allegedly said the infusions would “reduce the severity of symptoms, duration of illness, and therefore the contagiousness.”

Prosecutors noted that in one video, Mok admitted that Vitamin C has not been approved by the FDA or any other agency to treat or prevent the coronavirus. But despite resistance from his staff and lack of medical evidence, Mok allegedly threatened to fire those who did not perform the infusions on paying patients who potentially had the virus.

“If you won’t treat COVID patients in the fear that they would expose vein patients, you need to shut down!” Mok said during an April 15 management meeting to those clinics who expressed doubt, the complaint states.

In total, prosecutors allege Allure submitted at least 98 claims to insurance companies, including Medicare, related to unverified infusion therapy services for patients with the coronavirus. To date, 3,407 people have died and 38,210 more have been infected with the virus in Michigan, according Johns Hopkins University.

The doctor’s lawyer, Mark Kriger, declined The Daily Beast’s request for comment on Tuesday, stating he does not believe “it is appropriate to comment on pending cases.”

“The appropriate forum is the courtroom,” Kriger said.