A three-month Bloomberg investigation has found that Flynn, who was fired for having lied to the FBI and the vice president about his contacts with Russians, had a slew of other problematic entanglements. Previously unreported documents, including Pentagon contracts, emails and internal company papers, point to overlapping business conflicts around the world.

Self-dealing is, in some ways, at the core of the Mueller inquiry, which is looking at money laundering, contact with foreign (especially Russian) officials and a blending of personal profit with public policy. During the campaign, the transition and his few weeks as national security adviser, Flynn was in Trump’s inner circle. While it remains unclear what he’s providing Mueller, his history of mingling business with government could point investigators to look for similar overlaps among other Trump insiders.

“These conflicts of interest and hidden deals are highly relevant to what was going on with the Russians,” said Nick Akerman, a former Watergate prosecutor, noting that Flynn was in close touch with Russian Ambassador Sergei Kislyak while also being close to Trump. “His hidden business entanglements and his back channel communications with foreign governments raise a lot of possibilities.”