The Justice Department this weekend brought its first case of alleged fraud stemming from the coronavirus crisis, convincing a federal judge in Texas to issue a restraining order Sunday to block a website that claimed to be distributing vaccines.

In court documents, the department alleged the operator of the site, coronavirusmedicalkit.com, was facilitating a wire-fraud scheme, “intentionally making false statements” about the vaccines, which do not exist.

“The website falsely claims that the World Health Organization is giving away free vaccine kits and that individuals who visit the website can order such a kit by paying $4.95 for shipping,” the Justice Department wrote. “The World Health Organization is not offering free ‘vaccine kits’ for COVID-19. Indeed, there exists no known vaccine that is effective against COVID-19.”

It’s unclear how many people may have paid the website believing they would receive a vaccine.

U.S. District Judge Robert Pitman granted the department’s request for a temporary restraining order against the site and the entity that registered it — though as of 3:30 p.m. Sunday, it remained live.

“The Department of Justice will not tolerate criminal exploitation of this national emergency for personal gain,” said Assistant Attorney General Jody Hunt of the Justice Department’s Civil Division. “We will use every resource at the government’s disposal to act quickly to shut down these most despicable of scammers, whether they are defrauding consumers, committing identity theft, or delivering malware.”

The Justice Department did not identify who is behind the website. The civil case was filed as a “John Doe” complaint. The department wrote that the company NameCheap Inc. registered the site on behalf of an unknown person March 3, and officials sent a letter to NameCheap on Thursday informing it of the alleged fraud. Efforts to contact NameCheap’s chief executive were not successful.

Attorney General William P. Barr last week directed federal prosecutors across the country to prioritize the “detection, investigation, and prosecution of all criminal conduct related to” the novel coronavirus.

“The pandemic is dangerous enough without wrongdoers seeking to profit from public panic and this sort of conduct cannot be tolerated,” he wrote in a memo.

His deputy, Jeff Rosen, later issued similar guidance, telling all U.S. attorneys to appoint a coronavirus coordinator in their respective offices.

The coronavirusmedicalkit.com site is a simple one. Below an NBC News video clip about the crisis, it falsely claims the World Health Organization is “giving away vaccine kits” to people willing to pay $4.95 for shipping, and prompts users to click a button to “ORDER NOW.”

“You just need to add water, and the drugs and vaccines are ready to be administered,” the site says. “There are two parts to the kit: one holds pellets containing the chemical machinery that synthesises the end product, and the other holds pellets containing instructions that tell the drug which compound to create. Mix two parts together in a chosen combination, add water, and the treatment is ready.”

A Justice Department official, speaking on the condition of anonymity to discuss the ongoing investigation, said officials do not know who created the site, and it was possible it was registered with NameCheap by someone using a fake name or other cyber tools to hide their identity. The restraining order, the official said, also covers NameCheap, though there is no allegation the company has committed a crime.

The official said the Justice Department has recently set up systems to review consumer complaints about coronavirus, as well as conducted their own scouring of the Internet and news sites to “identify potentially problematic conduct.” U.S. attorneys across the country have in recent days been issuing public warnings about the problem.

In addition to sites selling fake products, law enforcement is concerned with telephone scams where callers claim someone’s relative has been diagnosed with covid-19 and they must wire money immediately to cover the cost of treatment.

“There’s fraudsters all over the world that will look at this epidemic as an opportunity,” the official said.