On Tuesday, President Donald Trump applauded his son’s “transparency” after he confirmed details of his meeting with a Kremlin-connected lawyer in hopes of obtaining damaging information about Hillary Clinton from the Russian government. But it seems that Donald Trump Jr. was hardly transparent at all when he published his e-mail exchange with Rob Goldstone, the music publicist who helped arrange the now-infamous June 9 meeting at Trump Tower between Trump Jr., Jared Kushner, Paul Manafort, and Russian attorney Natalia Veselnitskaya.

According to an explosive new NBC report, there was also at least one other person in the room that day: a Russian-American lobbyist and former Soviet counterintelligence officer who is suspected of having ties to the Kremlin. (In an earlier interview with NBC News, Veselnitskaya denied ties to the Russian government or ever having promised opposition research on Clinton. She acknowledged that she was accompanied by at least one man, but she did not identify him.)

The revelation that the president’s son, son-in-law, and campaign manager all met with an ex-spy—and that the White House failed to disclose his presence even after acknowledging that the June 9 meeting took place—represents a significant new development in the federal investigation into alleged collusion between the Trump campaign and Russia. While Trump surrogates have dismissed the meeting as a “nothing-burger,” Trump Jr.’s disclosure on Tuesday sent Washington into a tailspin and incited a contentious legal debate over whether the eldest Trump son had broken any laws. The president’s son has argued that the meeting does not constitute collusion because Veselnitskaya did not offer any “meaningful” information.

Online, speculation immediately swirled that the unidentified fifth person was Rinat Akhmetshin, a lobbyist for a group that Veselnitskaya founded to seek the repeal of the Magnitsky Act—a retaliatory measure the U.S. leveled against Moscow, blacklisting suspected human-rights abusers. “I wasn't there, so I’m just relying on the NBC report, but there is only one person who fits that profile,” Hermitage Capital founder Bill Browder, who spearheaded the Magnitsky Act, told Business Insider on Friday. “In the world of Russian intelligence, there is no such thing as a ‘former intelligence officer,’ ” he continued. “So in my opinion, you had a member of Putin’s secret police directly meeting with the son of the future next president of the United States asking to change U.S. sanctions policy crucial to Putin.”

Hours later, Akhmetshin confirmed that he had met with Trump Jr., Kushner, and Manafort last year. “I never thought this would be such a big deal, to be honest,” he told the Associated Press, describing the meeting as “not substantive,” but acknowledged that the group discussed damaging information about the Democratic National Committee. Per the AP: