Donald Trump Jr revealed on Tuesday that in June 2016 he agreed to meet a woman described by an intermediary as a Russian government lawyer who might have information about his father's Democratic election rival, Hillary Clinton, after initially saying the meeting focused on an adoption programme.
President Donald Trump wrote on Twitter in May that investigations by the US Department of Justice and Congress into whether his campaign colluded with Russian meddling in the election are a "witch hunt."
Several Trump associates have given incomplete or inaccurate accounts of whether they had contacts with Russian officials or people with ties to the Kremlin. Here is a summary of what is known:
Donald Trump Jr
Trump's eldest son, Trump Jr, on Tuesday posted on Twitter images of a June 2016 email chain between himself and Rob Goldstone, a publicist who helped arrange a meeting between Trump Jr and attorney Natalia Veselnitskaya.
Goldstone described Veselnitskaya as a "Russian government attorney" who had agreed to provide "official documents and information that would incriminate Hillary" that would be "very useful to your father," according to the exchange. Clinton lost to Trump in the 2016 presidential election.
Veselnitskaya has said she is a private lawyer and denies having Kremlin ties.
"If it's what you say I love it," Trump Jr responded. Trump Jr went on to meet with Veselnitskaya, along with Trump's son-in-law Jared Kushner and then campaign manager Paul Manafort on June 9, 2016, at Trump Tower in New York.
Trump Jr released his email exchange with Goldstone on Tuesday after the New York Times said it planned to write about their contents and sought his comment.
Trump Jr had previously called the June 2016 meeting a "short introductory meeting" that focused on the issue of child adoption.
In a March interview with the New York Times, Trump Jr said he was sure he met with people who were Russian at some point, but they were not related to the campaign.
"But none that were set up. None that I can think of at the moment. And certainly, none that I was representing the campaign in any way, shape or form," he told the newspaper.
Attorney General Jeff Sessions at his January confirmation hearing was asked by Democratic Senator Al Franken about allegations that Trump associates had contact with Russian officials about the presidential campaign.
"I'm not aware of any of those activities. I have been called a surrogate at a time or two in that campaign and I did not have communications with the Russians," Sessions responded.
The White House subsequently confirmed that Sessions had met with Russian Ambassador Sergei Kislyak at least twice during 2016. Sessions said at a March 2017 news conference that he did
not list the meetings because they were in his official capacity as a US senator and the campaign was not discussed.
At the same March news conference, Sessions recused himself from the Department of Justice's probe of alleged Russian meddling in the US election and possible collusion with Trump's campaign. Special Counsel Robert Mueller is now leading that probe.
Once Sessions was confirmed as attorney general, he was asked to list "any contact" he had with a foreign government or its associates on his security clearance form. He did not list any related to Russia, the Washington Post reported in May.
Former White House national security adviser Michael Flynn was forced to resign in February after less than a month in the role after it became known that he had failed to disclose the content of conversations he had with Kislyak and misled Vice President Mike Pence about their meetings.
Flynn, a retired lieutenant general, may have misled Pentagon investigators about his foreign contacts when he sought to renew his security clearance in 2016, according to documents obtained during a congressional probe into alleged Russian election meddling and collusion with Trump's campaign.
Flynn said during a security-clearance interview that all of his foreign trips taken as a private citizen were paid for by US companies. In fact, Russia Today, which the US considers a state-run propaganda arm, paid for Flynn to take a 2015 trip to Moscow. He sat next to Russian President Vladimir Putin at a gala dinner, according to a document released in May by congressional Democrats.
Trump's senior adviser and son-in-law Jared Kushner, who is married to daughter Ivanka Trump, also failed to disclose contacts with Russia when seeking his security clearance, the New York Times reported in April.
The White House disclosed in March that Kushner met with Kislyak at Trump Tower in December 2016, in addition to seeing Kislyak when he attended an April 2016 campaign speech in Washington. The White House said the December meeting was to establish "a line of communication." Kushner also did not disclose on his security clearance form a meeting with Vnesheconombank, a Russian state-owned bank.
Kushner also had phone calls with Kislyak between April and November 2016, Reuters reported. Kushner's attorney, Jamie Gorelick, said that Kushner had "no recollection" of the calls as he had participated in "thousands of calls in this time period."
Kushner also attended a portion of Trump Jr's meeting with Veselnitskaya in June 2016, the emails disclosed by Trump Jr showed.