Trump campaign email vendors are marketing an anti-aging cream with the help of conspiracy theories surrounding the 2016 murder of a Democratic Party staffer.

The ad hawking the wrinkle-fighting formula is very clearly a scam. Yet it found its way onto an email list managed by consultants who have worked for some of the most prominent politicians in the country, including President Donald Trump and Vice President Mike Pence.

Websites traced to the same GOP vendors, Indiana-based digital consultancy the Prosper Group and an affiliated firm, have promoted the same conspiracy theory: that Seth Rich, a staffer for the Democratic National Committee, was gunned down in Washington, D.C., last year due to his involvement in the hacking of the DNC and the release of thousands of internal emails by the group WikiLeaks.

That narrative has garnered attention on right-wing websites and social media—and even on cable news, thanks to Fox News host Sean Hannity’s “investigation” into the conspiracy theory. But the Prosper Group’s promotion of it is of particular note given the firm’s prominent client list: It has worked for the campaigns of Republican officials including Trump, Pence, Health and Human Services Secretary Tom Price, Wisconsin Gov. Scott Walker, and New Jersey Gov. Chris Christie.

The conspiracy theory’s continued traction underscores the degree to which many Americans have been swayed by so-called fake news that aligns with their ideological views, and how some have attempted to cash in on baseless—but widely shared—political stories.

Last week, the Prosper-linked Seth Rich conspiracy theorizing took a bizarre turn. An email marketing company run by the firm’s top two executives blasted out an advertisement that promoted a skincare product by linking it to the Seth Rich murder.

“Sean Hannity’s Wife Drops Bombshell Amidst Fox News Murder Investigation!” read the email’s subject line. It linked to “a message from our sponsor” that described in detail how Hannity’s dogged coverage of the Seth Rich murder had led to intense media scrutiny of the Fox host. “But what journalist [sic] found about [Hannity’s wife] Jill’s net worth is even more mindblowing,” the ad exclaimed. She had secretly devised a wrinkle-fighting skin cream called Parisian Secret, the ad says, that produces “anti-aging results that before now were only possible through surgeons.”

The whole thing appears to be a scam. The ad included fake Facebook comments from individuals who have reportedly been targeted by similar attempts to fraudulently convey their endorsements of various anti-aging products.

Hannity confirmed that the ad was “all a lie” in an email on Wednesday. “I have my attorneys on it. Fake news,” he wrote.

It wasn’t the first of these scams to appear on this particular email list, where messages appear from the sender “Lifelong Conservative.” Another “message from our sponsor” linked to an ad claiming that Parisian Secret was actually the creation of Facebook founder Mark Zuckerberg’s wife. Language in that ad is nearly identical to the one featuring Hannity. Additional ads for the same product attribute testimonials to to NBC News host Megyn Kelly, talk-show host Kelly Ripa, HGTV reality-television start Joanna Gaines, and “this 72 year old grandma.”

The Lifelong Conservative email list in is run by a company called Mustard Seed Interactive, and the skin cream email came from an advertiser to which Mustard Seed rented its list, according to Kurt Luidhardt, Prosper’s co-founder and vice president. Mustard Seed is a Prosper client, Luidhardt said in an email, but Prosper has no ownership interest in the company.

But at least on paper, Prosper’s ties to Mustard Seed appear to run deeper than those of its other clients. Incorporation records show that the firm is headquartered in the same suite of the same Greenwood, Indiana, building as Prosper. Luidhardt is Mustard Seed’s president, according to those records. Its only other listed executive is Kristen Luidhardt, Kurt’s wife and Prosper’s president.

Non-promotional emails from the Lifelong Conservative list feature conservative news and commentary. The stories they link to are almost uniformly hosted on the website DC Statesman, to which LifelongConservative.com, the web domain for that email list, directs. Prosper staffer Alan Moore serves as managing editor for DC Statesman and a sister site, Real Time Trump. That site’s web domain information says it was registered by Prosper and Kurt Luidhardt last year.

Both of the sites have promoted the Seth Rich conspiracy theory, including in articles authored by Moore. “We’re not one for conspiracy theories, but this definitely merits further investigation,” he wrote in a post that suggested Rich may have been killed for leaking DNC emails to WikiLeaks. “The circumstances are very suspicious.”

Luidhardt said that both DC Statesman and Real Time Trump are owned by Mustard Seed. He did not respond to follow-up questions about his specific role for that company. He also did not respond to inquiries about the firm’s promotion of a conspiracy theory that the Rich family has begged to be put to rest.

While their pleas have gone unheeded in some corners of the right-wing web—Hannity, for his part, agreed to stop pressing the story in May, then hinted at it again last week—its prevalence on Prosper-associated websites and email lists is particularly noteworthy due to the firm’s impressive roster of clients. Chief among them is President Trump himself. According to filings with the Federal Election Commission, the Trump campaign was by far Prosper’s top political client last year. The campaign paid the firm more than $650,000 for fundraising consulting and website development. Trump’s joint fundraising committee paid Prosper another $140,000.

According to its website, Prosper’s other clients have included gubernatorial campaigns for Pence, Walker, and Christie, Price’s House campaign, Nebraska Republican Sen. Ben Sasse’s campaign, and prominent groups such as the socially conservative Faith and Freedom Coalition. A handful of Republican congressional campaigns have already enlisted Prosper’s services this year, FEC records show.

Mustard Seed has also done significant work for high-profile Republican political groups, including email list sales and rentals to the 2016 presidential campaigns of Sen. Ted Cruz, Gov. John Kasich, and Sen. Marco Rubio, the Republican National Committee, the National Republican Congressional Committee, and Speaker Paul Ryan’s joint fundraising committee.

Prosper is also affiliated with Conservative Connector, a prominent Republican email list broker. Luidhardt co-founded that company, and it was initially led by Prosper’s director of special projects. Like Mustard Seed, Conservative Connector shares office space with Prosper, according to incorporation records. Luidhardt, who is listed as its registered agent, has said he is “part of a group of Republican digital agencies” that “run” the firm.

Conservative Connector struck gold during the 2016 election cycle, when the RNC paid the firm about $27 million for email list acquisition.

“The profits are absolutely enormous,” one prominent political email consultant told The Washington Post at the time. “If you are a list owner with a good list, you stand to make a lot, a lot of money.”