A report claims that a warrant to eavesdrop on Carter Page, a former Trump campaign aide, was improperly obtained.
Stephen K. Bannon, the president’s former chief strategist, will be interviewed by investigators for the special counsel rather than go in front of a grand jury.
The move marks the first time the special counsel is known to have used a grand jury subpoena to seek information from a member of President Trump’s inner circle.
White House officials viewed it as a sign the special counsel’s inquiry was nearly over. But it touched off discussions about the perils of the president sitting for an interview.
The first congressional criminal referral in connection with Russian meddling targeted a former British spy, not anyone accused of conspiracy.
The special counsel’s investigation has uncovered several incidents involving the president that raise questions about whether he obstructed justice.