The revelation adds to growing questions about who knew what and when among Mr Trump’s team about Russian meddling in the US presidential election
Trump Jr knew Russia was helping his father's campaign before he met Russian lawyer
The son of the US president, Donald Trump Jr, on Tuesday released the email chain of his correspondence with Rob Goldstone, a former British tabloid journalist who acted as a Russian intermediary.
“The Crown prosecutor of Russia met with [the father of a Trump business contact] this morning and in their meeting offered to provide the Trump Campaign with some official documents and information that would incriminate Hillary and her dealings with Russia and would be very useful to your father,” wrote Mr Goldstone.
“This is obviously very high level and sensitive information but is part of Russia and its government’s support for Mr Trump.”
Mr Trump Jr’s response offered no concern about the implications of such an offer: “If it’s what you say I love it especially later in the summer.”
The president's son was told in an email that the Russian government was making efforts to help his father’s run for the White House before agreeing to a meeting with a Kremlin-linked lawyer last year, according to The New York Times.
The meeting was held in June, soon after Donald Trump secured the Republican nomination for the presidency and shortly before hackers began releasing information stolen from the Democratic campaign.
The revelation adds to growing questions about who knew what and when among Mr Trump’s team about Russian meddling in the US presidential election.
It follows days of damaging leaks and represents the first allegation that Mr Trump Jr accepted the meeting with Natalia Veselnitskaya on the understanding he would be presented with damaging information about his father’s opponent that could have come from the Kremlin.
Members of the Senate intelligence committee are asking that everyone present at the Trump Tower meeting come forward for questioning while critics of the Trump administration say it is evidence of criminal collusion with Moscow.
A spokeswoman for the Democratic National Committee said: “Donald Jr was willing to accept the help of a hostile foreign government to sway the election. In the ensuing months, the Trump family watched as news of the Kremlin’s hacking campaign developed and they did nothing but celebrate and encourage it to continue.”
The email exchange once again puts the Trump administration on the back foot about relations with Moscow, adding to the sense that senior figures have not been transparent about contacts.
As more details have emerged, Mr Trump Jr has twice changed his story about the circumstances of the meeting.
At first, he confirmed the meeting had taken place but said it was held to discuss Moscow’s ban on American families adopting Russian babies. He later said he had been offered compromising material about Hillary Clinton, which failed to materialise.
“Her statements were vague, ambiguous and made no sense. No details or supporting information was provided or even offered. It quickly became clear that she had no meaningful information,” he explained, before adding the offer of information appeared to be a ruse to discuss the adoption ban.
The new details add a further twist to how much he knew before agreeing to the meeting.
Adam Schiff, the senior Democrat on the House Intelligence Committee, pointed out that the meeting happened after Russian hackers are believed to have stolen information on Mrs Clinton but before it was made public.
"So, if this is correct, the first person who may have found out that the Russians had decided not just to gather information about what the candidates' positions might be or what they might do in office, but they had made a decision to intervene to try to help a candidate — the first person who may have learnt that was the president's son through this email,” he told MSNBC.
However, in an interview with NBC News on Tuesday, Ms Veselnitskaya insisted she was not working for the Kremlin and had no damaging information about the Clinton campaign.
“It is quite possible that maybe they were longing for such an information,” she said. “They wanted it so badly that they could only hear the thought that they wanted.”
She added that Jared Kushner, Mr Trump’s son-in-law, and Paul Manafort, then the campaign manager, were also present although she was not introduced to them.
Mr Trump’s supporters insist there was nothing untoward and that gathering information on opponents is part and parcel of the modern campaign.
Alan Futerfas, a lawyer retained by Mr Trump Jr, described the controversy as “much ado about nothing”.
“Don Jr's takeaway from this communication was that someone had information potentially helpful to the campaign and it was coming from someone he knew. Don Jr had no knowledge as to what specific information, if any, would be discussed," he said.
For his part, Mr Trump Jr said he was happy to appear before the Congressional investigations into Russian meddling.
“Happy to work with the committee to pass on what I know,” he wrote on Twitter.