A New York Times report Tuesday that Lebanese-American businessman George Nader, who was served with a grand jury subpoena in January after arriving in the U.S. en route to Mar-a-Lago to celebrate President Trump’s first year in office, has been cooperating with Robert Mueller’s investigation, including testifying before a grand jury last week, is the latest indication that Mueller’s investigative team is eyeing a January 2017 meeting in the Seychelles as a possible financial link between Trump World and Russia.

Nader serves as an adviser to the ruler of the U.A.E., Crown Prince Mohammed bin Zayed Al-Nahyan, who called the meeting on the small island nation off the east coast of Africa that was attended by Nader, Russian investor and Putin confidante Kirill Dmitriev, and founder of the private security firm Blackwater Erik Prince, who has also been an informal Trump adviser.

“Mr. Mueller appears to be examining the influence of foreign money on Mr. Trump’s political activities and has asked witnesses about the possibility that the adviser, George Nader, funneled money from the Emirates to the president’s political efforts,” the Times reports. “Mr. Nader’s presence at the Seychelles meeting appears to connect him to the primary focus of Mr. Mueller’s investigation: examining Russian interference during the 2016 presidential campaign.”

The exact purpose of the Seychelles meeting remains unclear, but the men who attended have multiple overlapping histories, relationships, and interests. Nader used to work at Blackwater as a consultant and introduced Prince, the company’s founder, to Dmitriev, a former Goldman Sachs banker who was picked by Putin to manage an unconventional Russian state-run investment fund that in 2013 was the recipient of $6 billion in funding from Abu Dhabi. “Mr. Dmitriev became a frequent visitor to Abu Dhabi, and Emirati officials came to see him as a key conduit to the Russian government,” according to the Times. “In the weeks after the 2016 presidential election, Crown Prince Mohammed aroused the suspicions of American national security officials when they learned that he had breached protocol by visiting Trump Tower in Manhattan without notifying the Obama administration of his visit to the United States.”