A Russian-American lobbyist accompanied a Russian lawyer to a summer 2016 meeting with Donald TrumpDonald John TrumpO’Malley tells Dems not to fear Trump Right way and wrong way Five things to know about the elephant trophies controversy MORE Jr., The Associated Press reports. 

Rinat Akhmetshin confirmed to the AP that he was in attendance at the meeting with Trump Jr. and the lawyer Natalia Veselnitskaya.

A separate report from NBC News stated that an unnamed former Soviet counterintelligence officer was in the Trump Jr. meeting.

Akhmetshin is a former member of the Russian military intelligence services, known in the U.S. as GRU, but is now an American citizen. He told the AP suggestions that he has ties to Russian intelligence are part of a "smear campaign" against him, adding that he wasn't trained as a spy.

The new detail about Akhmetshin's involvement in the meeting is the latest wrinkle in the Russia story that has rocked Washington this week.

The meeting was prompted by emails to Trump Jr. that promised damaging information on then-Democratic presidential nominee Hillary ClintonHillary Diane Rodham ClintonO’Malley tells Dems not to fear Trump FBI informant gathered years of evidence on Russian push for US nuclear fuel deals, including Uranium One, memos show Pelosi blasts California Republicans for supporting tax bill MORE.

Trump Jr. has said no such information was provided by Veselnitskaya, who instead wanted to talk about the separate issue of a U.S. law targeting Russians for human rights abuses known as the Magnitsky Act and countermeasures from Russia prohibiting U.S. adoptions of Russian children.

President Trump's son-in-law Jared Kushner and then-campaign chairman Paul Manafort were also present for the meeting. 

What remains unclear is who, other than Akhmetshin, attended the meeting with Veselnitskaya.

An attorney for Trump Jr., Alan Futerfas, told The Hill that three people in addition to Veselnitskaya came to the meeting as part of her envoy.

Futerfas would not reveal the names of the others in the envoy, but said the lobbyist identified in the NBC report was introduced as a friend of Veselnitskaya and Emin Agalarov, the Russian pop star whose agent, Rob Goldstone, arranged the meeting.

“He’s a U.S. citizen and not working for the Russian government and my client was introduced to him literally at the meeting,” Futerfas said. 

"[Trump Jr.] didn’t know the name before and had no recollection after that. He was introduced either as a friend of Emin’s or of Natalia’s. Basically he helped translate because Natalia’s English is not that good. He’s a U.S. citizen.

"All I can say is Trump Jr. met him for the first time and learned his name minutes before the meeting and he was introduced as a friend." 

Trump Jr.'s meeting with Veselnitskaya was first reported over the weekend by The New York Times. On Tuesday, Trump Jr. tweeted out emails with Goldstone that detailed how the meeting was arranged.

In one of the emails, Goldstone writes that the information being offered “would incriminate Hillary and her dealings with Russia and would be very useful to your father.”

“This is obviously very high level and sensitive information but is part of Russia and its government's support for Mr. Trump,” Goldstone continued.

“If it's what you say I love it especially later in the summer,” Trump Jr. replied.

Democrats are pointing to the meeting as proof that Trump's campaign sought to collude with Moscow amid its efforts to meddle in last year's presidential election.

The White House says nothing substantial came out of the meeting, and Trump has said "most people" would have taken the opportunity to get opposition research on a campaign opponent.

Updated at 10:51 a.m. Jonathan Easley contributed.