FBI leadership concealed Sussmann’s identity from field investigators, agent testifies

FBI leaders pulled field agents from other investigations in 2016 to pursue a false tip linking presidential candidate Donald Trump to a Russian bank, but they concealed that the probe was spurred by information provided by rival Hillary Clinton’s campaign, an FBI agent testified in court Monday.

Top bureau officials sent an electronic communication marking the opening of the case and saying the investigation was based on a “referral” from the Justice Department rather than a tip from Michael Sussmann, an attorney for Mrs. Clinton’s campaign.

The communication was sent four days after Mr. Sussmann provided...