A little-known company located in Switzerland has come under scrutiny by the Special Counsel’s Office for its connection to Psy Group, the firm that created a social-media manipulation plan to help Donald Trump win the 2016 election. That’s according to three sources with knowledge of the office’s questioning, and documents obtained by The Daily Beast.

Former employees of Psy Group said the FBI interviewed them in 2017 and asked detailed questions about the firm’s business and ownership structure. These same sources told The Daily Beast that while working at Psy, which is now defunct, they operated under the understanding that Joel Zamel, an Australian with links to Israeli intelligence, ultimately owned the firm. But the financial structure of Psy Group was much more complicated, they said, and included offshore entities registered in the British Virgin Islands.

At the end of that chain of opaque offshore entities sits a Zurich-based financial-services group known as Salix Services AG, according to interviews with former Psy Group employees and two other individuals with insight into the firm’s ownership. And financial documents appear to show a relationship between Salix, named after the Latin word for a willow tree, and at least one of the companies that owned Psy Group.

Robert Mueller’s team has eyed Salix as part of his wide-ranging probe into foreign meddling in the 2016 presidential election. Details about Psy Group’s financials and its ties to Salix could shed new light on a pair of mysteries that could be key to this part of the special counsel’s probe: Why did international business and influence-peddler George Nader pay Zamel $2 million after the election? And where did all that money go?

On its blander-than-bland website, Salix offers few clues about its operations. (“Like the Willow, at Salix our roots as well are deep and run wide through a network of clients, professional intermediaries, financial institutions and family offices,” the site reads.) And the company did not immediately respond to a request for comment. Zamel’s lawyer declined to comment. The Special Counsel’s Office declined to comment.

For more than a year, Psy Group and its owner, Zamel, have flown somewhat under the radar, despite the questions they’ve faced about their efforts to use online propaganda to help Trump win the presidency.

The New York Times was the first to detail Psy Group’s plan. And on Monday, The New Yorker published a detailed story about the firm and its operations, calling it a “Private Mossad for Hire.” But Zamel’s involvement in any plan to help Trump win through an online propaganda campaign has remained somewhat elusive. Former Psy Group employees previously told The Daily Beast that they believed Zamel could have carried out a plan separate from the one they pitched to Trumpworld in 2016.

In August 2016, Zamel met with former Blackwater founder Erik Prince, Donald Trump Jr., and Nader to discuss ideas that could potentially help Trump win the election. During that meeting, as first reported by the Times and later confirmed by The Daily Beast, Nader told the room that the crown princes of both Saudi Arabia and the UAE were eager to help Trump win the election.

Zamel, through his lawyer, has previously denied pitching an official plan for the campaign or working with campaign members. Two other sources close to the Trump team said they did not believe Zamel, or Psy Group, carried out an official cybercampaign. But according to The New Yorker, Zamel told Nader after the election, “Here’s the work that we did to help get Trump elected.”

Nader’s payment of $2 million after the election went through to Zamel. Exactly what for—that’s unknown. The ultimate beneficiary could offer clues.

Lawyers for Zamel—a self-styled Mark Zuckerberg of the national-security world—have previously refused to say how much of a stake he held in Psy Group and therefore how much controlling power he had over the company. But records obtained by The Daily Beast show Zamel is a director of the company that owns Psy.

Furthermore, documents reviewed by The Daily Beast and interviews with individuals familiar with Psy Group’s financial structure lay bare a complex web of companies with connections to Zamel that point to Salix.

“It’s how Joel holds his shares,” one former Psy Group employee told The Daily Beast. “They set up trusts and provide nominee services to… shield beneficial owners from their holdings. It’s completely legal.”

Psy Group, registered as Invop in Israel, has its ownership obscured by a series of offshore companies. In June 2018, after the company’s name surfaced in the Mueller investigation, employees asked an Israeli court to liquidate the company and financial records revealed that all of Psy Group’s shares were owned by a Cyprus-registered company known as IOCO Limited. Former Psy Group employees also told The Daily Beast that IOCO was “just another name for Psy.”

Since its creation in 2014, IOCO’s shares have been owned by a handful of companies registered to post-office boxes in the British Virgin Islands. Bank records show that ownership of IOCO changed hands on a roughly annual basis through a rotating cast of anonymous offshore companies.

There are few hints about who owns the handful of companies that hold IOCO’s shares, but at least one of the companies listed as a former IOCO owner has links back to Salix.

Leaked documents from the Panamanian law firm Mossack Fonseca show that a company named Cornell Enterprises SA was at one point a shareholder of Prime Nominees Limited, IOCO’s sole shareholder from late 2015 through mid-2016. Salix is listed in the International Consortium of Investigative Journalists’ Panama Papers as an intermediary of Cornell, and Cornell shared an address with Salix in Zurich, Switzerland.

Protexer Limited, another former owner of IOCO, is listed as a subsidiary of the Trident Trust Company (Cyprus) Ltd., which currently serves as a secretary on the board of IOCO.

IOCO appears to have fallen on hard times itself. In December, the company announced a voluntary liquidation by its creditors scheduled for January 2019.

Meanwhile, former Psy Group employees believe they’ve been “cleared” by law enforcement in the U.S., they told the Daily Beast, and do not expect to face more questioning. Zamel appears to still be operating his other major global consulting firm, Wikistrat, which holds contracts with the U.S. government.