Donald Trump Jr. acknowledged Monday he made time for the meeting hoping to get information about Clinton.
Attorney Alan Futerfas said the man was described as a friend of Emin Agalarov, a Russian pop star who was a client of Rob Goldstone, a music publicist who had arranged the meeting, and possibly of Ms Velenitskaya's, NBC said.
Although Trump Jr. has insisted that Vesenikstaya mainly wanted to talk about Russian adoptions, Akhmetshin said she brought a folder with information about an American hedge fund operating in Russia that she believed was funneling money to the Democratic National Committee.
Sen. Mark Warner, the top Democrat on the Senate intelligence committee, told CNN the panel will ask Jared Kushner and Donald Trump Jr. for additional documents, following revelations from an email chain that Trump Jr released this week.
Futerfas told NBC that he spoke with the "friend", but it is not clear if that person is the same one who US officials suspect could have ties to Russian intelligence.
The Senate Judiciary Committee is reviewing records from the Department of Homeland Security (DHS) on Rinat Akhmetshin, the former Soviet intelligence officer who met with Donald Trump Jr.in June 2016.
The meeting came amid a lobbying campaign against the Magnitsky Act, legislation passed in 2012 that barred several Russian officials accused of human rights abuses from entering the US and infuriated Russian President Vladimir Putin.
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Trump Jr. helped arrange and attended the meeting for the goal of obtaining compromising information against his father's Democratic opponent, Hillary Clinton.
On Tuesday, Trump Jr. "He said absolutely not", Trump said.
Akhmetshin told the AP he tagged along with Veselnitskaya for the meeting, where they were also joined by an interpreter.
'I think it would be a dereliction of duty not to give it an honest look, ' he said. Charles Grassley, R-Iowa, told local reporters Wednesday.
"Obviously what they came up with didn't make a lot of sense, and it all fizzled out", Browder said.
Manafort, who resigned as Trump's campaign manager in August 2016 after about five months on the job, is under investigation by the FBI for business dealings and lobbying efforts associated with Ukrainian political campaigns.
They understand that if they ask for something big such as the repeal of a major human rights bill they have to offer something in return, he said, and in Trump's case they offered information on Clinton as stories swirled that Democratic Party servers had been hacked by Russian Federation.
On Thursday, Republicans on the House Appropriations Committee voted unanimously to block two amendments to address members of the Trump administration who are under investigation for possibly conspiring with Russian Federation, particularly Trump's son-in-law and close adviser, Jared Kushner.