Donald Trump Jr. told the Senate Judiciary Committee that he couldn't remember whether he had discussed the Russian investigation with his father.
The material, which includes interview transcripts and other "exhibits", is available here.
"It did not talk about what got them into the door, and I didn't expand on it because I didn't think it was relevant to discuss what the meeting was not actually about", Trump Jr. said of the initial Air Force 1 statement.
According to the transcripts, Trump Jr. also said he didn't think there was anything wrong with attending the Trump Tower meeting in which he was promised dirt on Hillary Clinton. He said he desperately needed a lawyer, wanted to speak publicly about the case but couldn't because the Trump lawyers wouldn't let him and was hoping to be compensated by the Agalarovs for his troubles.
Mr Trump Jr deflected multiple questions during the interview, saying he could not recall whether he discussed the Russian Federation probe with his father and whether he spoke with Mr Trump on the day the meeting was arranged.
Trump Jr. convened the meeting with his brother-in-law, Jared Kushner, and the campaign's then-chairman, Paul Manafort.
The younger Trump said the Russian visitors briefly indicated that some "business people who were supporters of the DNC and perhaps Hillary Clinton were in some sort of tax scheme to avoid paying taxes in both the United States and Russia".
About 2,500 pages of documents were released on Wednesday, including the interviews with Trump Jr. and Rob Goldstone, a music publicist who arranged the meeting and said in text messages it was part of a Russian government effort to aid the Trump campaign.
The meeting has been the subject of controversy, particularly the question of whether then-candidate Trump knew about it. "The public can now see that for over five hours I answered every question asked and was candid and forthright with the committee". He did so after receiving emails that described an outreach, via a series of intermediaries, from Russia's top federal prosecutor, Yuri Chaika, offering help to the Trump campaign.
He also said that it was important to note that when he accepted the invitation to go to the meeting there was "no focus on Russian activities" surrounding the campaign and claimed that Goldstone had not even confirmed the names of the attendees who would join them at the meeting.
Members of Congress and the Justice Department are investigating.
In an interview a year ago with the Senate Judiciary Committee, Trump Jr. downplayed his father's role in the entire matter.
The judiciary panel's 10 Democrats, in their joint response to the transcript release, noted that interviews turned up signs of dejection among the Trump allies present about the meeting's lack of more coherent negative material on Clinton.
The Trump campaign has dismissed the meeting as part of a bait-and-switch Russian lobbying effort to amend the Magnitsky Act.
Trump Jr. said at the end of the 20-minute meeting that the adoption issue would be revisited if his father became president, Anatoli Samochornov, who served as translator at the meeting for Veselnitskaya, told the Senate committee staff.
The committee did not interview Natalia Veselnitskaya, the Russian lawyer at the centre of the meeting.
The House intelligence committee cited Trump Jr.'s denials in completing its report about the Russia imbroglio with a finding that there had been no collusion between the Trump camp and the Russian active measures.