Mueller seeks White House documents on Flynn

In interviews with potential witnesses in recent weeks, prosecutors and F.B.I. agents have spent hours poring over the details of Mr. Flynn’s business dealings with a Turkish-American businessman who worked last year with Mr. Flynn and his consulting business, the Flynn Intel Group.

The company was paid $530,000 to run a campaign to discredit an opponent of the Turkish government who has been accused of orchestrating last year’s failed coup in the country.

Investigators want to know if the Turkish government was behind those payments — and if the Flynn Intel Group made kickbacks to the businessman, Ekim Alptekin, for helping conceal the source of the money.