An adviser to the de facto leader of the United Arab Emirates (UAE) is cooperating with investigators and gave testimony to a grand jury last week as part of special counsel Robert Mueller's probe, The New York Times reported Tuesday night.

George Nader, a Lebanese-American businessman who advises Crown Prince Sheikh Mohammed bin Zayed al-Nahyan, is cooperating as investigators reportedly examine whether Nader funneled money from the UAE in an attempt to influence President Trump's policies.

The special counsel's team has taken an interest in a January 2017 meeting in the Seychelles that Nader attended, the Times reported. Also in attendance was a Russian investor connected to President Vladimir Putin, and Erik Prince, a founder of Blackwater who advised Trump during the transition.

Nader was reportedly first served search warrants and a subpoena after landing at Dulles International Airport outside Washington, D.C., on Jan. 17. He planned to continue on to Florida to celebrate the president's first year in office at Trump's Mar-a-Lago estate but was held up by FBI investigators, who questioned him for two hours and took his electronics, the Times reported.

Since then, Mueller's team has questioned him multiple times about his meetings with Jared Kushner, Stephen Bannon and other officials, the newspaper reported.

Reports of Nader's cooperation come as Mueller is said to be expanding the scope of his investigation to look into Trump's past financial dealings.

Four former Trump campaign associates have thus far pleaded guilty or been indicted as part of Mueller's investigation. Mueller also filed charges last month against 13 Russian nationals and three Russian organizations for allegedly meddling in the 2016 election.