Blumenthal: Mueller should look into Nader meeting with Trump team, UAE

"The motive in a criminal prosecution is clearly important -- particularly if it is a corrupt motive, if it involves compromising confidential information or a position of trust -- and so the grand jury ought to be very interested in what George Nader has to say about the substance of that conversation at that meeting and others involving him in other parts of the world. The special counsel probably knows -- not probably knows, but certainly knows -- more than we do, and that meeting was significant," he said on CNN's "Erin Burnett OutFront."

Nader, a low-profile diplomatic go-between with ties to Trump's team who has forged close ties to the UAE, was stopped and questioned by the FBI at Washington Dulles International Airport in January as he returned from an overseas trip, sources say. Since then, he has been talking to Mueller's investigators and providing information to the grand jury.

Nader attended a December 2016 meeting in New York between Emirati officials and members of Trump's inner circle, and another in January 2017 in the Seychelles islands between the Emiratis and Erik Prince, a Trump associate. Nader was also in the Seychelles when Prince met with a Russian banker, the sources said.

The special counsel's questions about the Emiratis point to an investigation that has expanded beyond Russian meddling in the 2016 US election to broader concerns about foreign influence during the presidential campaign and long after it concluded. The Washington Post reported last week that at least four countries, including the United Arab Emirates, have discussed ways they could compromise Jared Kushner, the President's son-in-law and adviser.

While there is no indication that Nader is suspected of wrongdoing, his knowledge of key meetings involving the Emiratis and others could be helpful to the special counsel in understanding the inner workings of the transition and possible efforts to influence key figures in the administration.