WASHINGTON — Earlier this year, a Russian-American lobbyist and another businessman discussed over coffee in Moscow an extraordinary meeting they had attended 12 months earlier: a gathering at Trump Tower with President Donald Trump’s son, his son-in-law and his then-campaign chairman.

The Moscow meeting in June, which has not been previously disclosed, is now under scrutiny by investigators who want to know why the two men met in the first place and whether there was some effort to get their stories straight about the Trump Tower meeting just weeks before it would become public, The Associated Press has learned.

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 — and obtained their text message communications, people familiar with the investigation told the AP.

Special counsel Robert Mueller’s team also has been investigating the 2016 Trump Tower meeting, which occurred weeks after Trump had clinched the Republican presidential nomination and which his son attended with the expectation of receiving damaging information about Democrat Hillary Clinton. A grand jury has already heard testimony about the meeting, which in addition to Donald Trump Jr., also included Jared Kushner, Trump’s son-in-law, and his then-campaign chairman Paul Manafort.

The focus of the congressional investigators was confirmed by three people familiar with their probe, including two who demanded anonymity to discuss the sensitive inquiry.