Congressional investigators are asking why two men met at Trump Tower with Trump campaign officials in 2016 and met last summer in Moscow to discuss the gathering again.
Three people familiar with the focus of the congressional investigators have discussed aspects of the probe with The Associated Press.
Congressional investigators have questioned both men - lobbyist Rinat Akhmetshin and Ike Kaveladze, a business associate of a Moscow-based developer and former Trump business partner.
The Trump Tower meeting included Donald Trump Jr., Trump son-in-law Jared Kushner and campaign chairman Paul Manafort. Trump Jr. attended the meeting with the expectation of receiving damaging information about Democrat Hillary Clinton.
A lawyer for Kaveladze, Scott Balber, denies that the meeting last summer was an effort by the two men to get their stories straight.