As 2016 campaign season neared, a Russian national who special counsel Robert Mueller now believes was working with the country’s intelligence services founded a consulting firm in Washington, D.C.

Begemot Ventures International was incorporated in February 2015, occupying an office on Constitution Avenue. Like other firms in the nation’s capital it offered services catering to the politically inclined. But unlike those other shops, Begemot had executives tied not just to an alleged Russian influence campaign, but also a controversial data firm that would later help elect President Donald Trump.

The space that the firm continues to occupy also houses the offices of Sam Patten, a Republican lobbyist and foreign policy consultant who had previously worked to hone the firm Cambridge Analytica’s microtargeting operation during the 2014 midterm election cycle. They don’t just share a location either. Patten is listed as one of two Begemot executives in D.C. incorporation records.

The other is Konstantin Kilimnik, who is currently front-and-center in the federal investigation into Russian government meddling in the 2016 presidential election. A recent court filing by Mueller alleged that “Person A”—believed to be Kilimnik—“has ties to Russian intelligence service and had such ties in 2016.”

Kilimnik has a years-long professional relationship with former Trump campaign chairman Paul Manafort, whom Mueller has accused of illegally advancing the interests of foreign clients in the U.S. Kilimnik was a frequent intermediary between Manafort and Russian billionaire Oleg Deripaska, to whom Manafort offered private briefings on the 2016 presidential race. Kilimnik has long been suspected of having worked with or for Russian intelligence services in the past. But Mueller’s allegations are so explosive because they allege such ties continued through the presidential election—ties that would, by virtue of Kilimnik’s association with Manafort, represent the Trump campaign’s closest known link to Kremlin operatives.

But those close to Kilimnik say the allegations are at a minimum overblown, and at most an outright fabrication. Patten too rejected allegations of Kilimnik’s Russian intelligence ties in an interview this week.

Patten acknowledged his collaboration with Kilimnik on Begemot, which he said operates entirely abroad despite its D.C. address. Patten also confirmed his work with Cambridge Analytica, saying he assisted the firm’s U.S. operations in 2014, and also worked with the company on “several overseas campaigns.” He declined to go into further detail, citing a nondisclosure agreement, but stressed that his work for Begemot and Cambridge Analytica were entirely separate.

Cambridge Analytica did not respond to a request for additional information.

There is little public information about Begemot, whose name literally translates (from Russian) to hippopotamus but also may be a reference to a character in the Russian novel The Master and Margarita. Its emergence on the political scene—and the principles involved in its creation—underscore the smallness of the universe of Republican operatives and foreign policy hands who have done business with those at the center of the Russia investigation.

Begemot’s website says it “helps its clients win elections, strengthen political parties, build the right arguments before domestic and international audiences, and achieve better results.” But it doesn’t disclose any of those clients, or even the countries in which they operate. Patten declined to go into any detail about its work.

Patten’s relationship with Kilimnik goes back nearly two decades, when they worked together at the International Republican Institute, a GOP-aligned foreign policy group. In 2007 and 2008, Patten was an undersecretary of state for Democracy and Global Affairs in the Bush administration. He has also lobbied for political parties in Iraq and Georgia, and currently represents a group called the Committee to Destroy ISIS, a campaign funded in part, records show, by a Jordanian construction company.

“I operate in a small niche,” Patten said of his work.

Patten’s association with Cambridge Analytica began in 2014. His personal website says he worked with the firm “to introduce new technologies and methodologies to U.S. campaigns during the 2014 congressional cycle.” The “beta run” of Cambridge Analytica’s microtargeting efforts, the website says, was “adopted by at least one major U.S. presidential candidate.” At the time the website was written, Patten said, Cambridge Analytica was working on behalf of Sen. Ted Cruz (R-TX), though Patten never worked on behalf of the Cruz campaign. Cambridge Analytica would later work to elect Trump.

The data firm is at the center of controversy over the use of social media data in political micro-targeting efforts. A Cambridge Analytica whistleblower claims the company pilfered data from Facebook for use on behalf of its political clients. The company denies any wrongdoing. And Trump campaign officials have tried to downplay the efficacy of the firms work, even though the campaign spent nearly $6 million for its services.

Mueller’s team is examining the role that Cambridge Analytica played in Trump’s election victory, but there is no indication that Patten’s work for the firm is problematic or of any interest to the special counsel’s investigation. Patten himself played down the connection, saying his work for the firm was “wholly unconnected” to Begemot and Kilimnik.

Begemot, Patten said, “is a privately-held, small consulting company that has provided public relations and political strategy advice for clients outside the United States, and [is] not related to the ongoing circus here.”

Patten expressed skepticism about Mueller’s recent allegations about his colleague. “A lot of people in our country wish Mueller well. If this is his ace in the hole, I am profoundly depressed,” he said.

“I have no reason to suspect him of being a Russian agent,” Patten added. “For people to continuously repeat the ‘in contact with/working with Russian intel’ epithet about anyone who lives or works in a country ruled by an ex KGB officer is rather absurd.” Such a description, he said, could include “anyone who rides the Moscow metro.”