Donald Trump Jr.’s June 2016 meeting with a Kremlin-linked lawyer is officially part of the special counsel investigation into collusion between the Trump campaign and Russia, CNN reported Tuesday.

Three U.S. officials familiar with the investigation told the network that special counsel Robert Mueller’s team only recently learned about the meeting, which Trump’s son-in-law and senior adviser, Jared Kushner, divulged on his recently amended application for a security clearance.

A separate U.S. official briefed on the matter told CNN that federal investigators will look into the sit-down that the President’s son agreed to have with an individual described by an acquaintance in an email as “a Russian government attorney” who had “high level and sensitive information” that would “incriminate” Hillary Clinton.

“I love it,” Trump Jr. replied in one of a series of bombshell of emails detailing the lead-up to that meeting, which he published in full on Twitter on Tuesday to the shock of the political world.

Both the emails and the meeting are now part of Mueller’s investigation, a source told CNN.

Kushner and then-campaign chairman Paul Manafort confirmed their attendance at the Trump Tower sit-down to The New York Times, but did not answer additional questions about it.