In an email last summer, former Trump adviser George Papadopoulos claimed that top campaign officials had agreed to a meeting with representatives of Russian President Vladimir Putin.
The message, if true, would bolster claims that Trump's campaign attempted to collude with Russian interests.
But it is unclear whether Papadopoulos, who pleaded guilty to lying to the Federal Bureau of Investigation, was merely boasting when he sent the July 14 email to a Kremlin-linked contact. There is also no indication such a meeting ever occurred.