A Russian-American lobbyist says he attended a June 2016 meeting with US President Donald Trump’s son, marking another shift in the account of a discussion that was billed as part of a Russian government effort to help the Republican’s White House campaign.

Rinat Akhmetshin confirmed his participation to The Associated Press.

He has been reported to have ties to Russian intelligence agencies, though he denied ever working as an intelligence agent.

He told AP that he served in the Soviet military in a unit that was part of counterintelligence but was never formally trained as a spy.

The meeting has heightened questions about whether Mr Trump’s campaign coordinated with the Russian Government during the election, which is the focus of federal and congressional investigations.

In emails posted by Donald Trump Jr earlier this week, an associate who arranged the meeting said a Russian lawyer wanted to pass on negative information about Democrat Hillary Clinton.

The associate stated that the discussion was part of a Russian Government effort to help the GOP candidate.

While Donald Trump Jr confirmed that Russian attorney Natalia Veselnitskaya was in the meeting, he did not disclose Mr Akhmetshin’s presence.

Rinat Akhmetshin pictured in Washington in 2016. Photo: AAP

The President’s son has tried to discount the meeting, saying that he did not receive the information he was promised.

Mr Akhmetshin said Ms Veselnitskaya presented the Trump associates with details of what she believed were illicit funds that had been funnelled to the Democratic National Committee.

She suggested that making the information public could help the Trump campaign.

“This could be a good issue to expose how the DNC is accepting bad money,” Mr Akhmetshin recalled her saying.

Mr Trump Jr asked the attorney if she had all the evidence to back up her claims, but Ms Veselnitskaya said the Trump campaign would need to research it more. After that, Mr Trump Jr lost interest, according to Mr Akhmetshin.

“They couldn’t wait for the meeting to end,” he said.

June 2016 meeting ‘not substantive’: lobbyist

Jared Kushner, Mr Trump’s son-in-law and current White House senior adviser, and then-campaign chairman Paul Manafort also attended the meeting.

Asked about Mr Akhmetshin’s participation in the meeting, Manafort spokesman Jason Maloni declined to comment.

A spokesman for Mr Kushner did not respond to inquiries, nor did Mr Trump Jr’s attorney.

Mr Akhmetshin said the attorney brought with her a plastic folder with printed-out documents.

He said he was unaware of the content of the documents or whether they were provided by the Russian Government, and it was unclear whether she left the materials with the Trump associates.

Mr Akhmetshin said the meeting was “not substantive” and he “actually expected more serious” discussion.

“I never thought this would be such a big deal to be honest,” he said.

The Russian Government has denied any involvement or knowledge of the June 2016 meeting.

Asked about Mr Akhmetshin, Russian President Vladimir Putin’s spokesman, Dmitry Peskov, told reporters: “We don’t know anything about this person.”