Just before the stroke of midnight on September 20, 2016, at the height of last year’s presidential election, the WikiLeaks Twitter account sent a private direct message to Donald Trump Jr., the Republican nominee’s oldest son and campaign surrogate. “A PAC run anti-Trump site putintrump.org is about to launch,” WikiLeaks wrote. “The PAC is a recycled pro-Iraq war PAC. We have guessed the password. It is ‘putintrump.’ See ‘About’ for who is behind it. Any comments?” (The site, which has since become a joint project with Mother Jones, was founded by Rob Glaser, a tech entrepreneur, and was funded by Progress for USA Political Action Committee.)

The next morning, about 12 hours later, Trump Jr. responded to WikiLeaks. “Off the record I don’t know who that is, but I’ll ask around,” he wrote on September 21, 2016. “Thanks.”

The messages, obtained by The Atlantic, were also turned over by Trump Jr.’s lawyers to congressional investigators. They are part of a long—and largely one-sided—correspondence between WikiLeaks and the president’s son that continued until at least July 2017. The messages show WikiLeaks, a radical transparency organization that the American intelligence community believes was chosen by the Russian government to disseminate the information it had hacked, actively soliciting Trump Jr.’s cooperation. WikiLeaks made a series of increasingly bold requests, including asking for Trump’s tax returns, urging the Trump campaign on Election Day to reject the results of the election as rigged, and requesting that the president-elect tell Australia to appoint Julian Assange ambassador to the United States.

“Over the last several months, we have worked cooperatively with each of the committees and have voluntarily turned over thousands of documents in response to their requests,” said Alan Futerfas, an attorney for Donald Trump Jr. “Putting aside the question as to why or by whom such documents, provided to Congress under promises of confidentiality, have been selectively leaked, we can say with confidence that we have no concerns about these documents and any questions raised about them have been easily answered in the appropriate forum.” WikiLeaks did not respond to requests for comment.