Buried in special counsel Robert Mueller's 400-plus page report is the question of whether then-president-elect Donald Trump attended a 2016 championship chess tournament — an event that came under scrutiny as Mueller probed possible collusion between Trump's orbit and the Russian government.

Although Trump said he did not attend the event, he told Mueller in written answers that he became "aware of documents indicating" that then-president of the World Chess Federation (FIDE) Kirsan Ilyumzhinov — a sanctioned Russian power player — invited the Trump Organization in March 2016 to host the tournament at Trump Tower.

"I do not remember having been asked to attend the World Chess Championship gala, and I did not attend the event," Trump told Mueller. "During the course of preparing to respond to these questions, I have become aware of documents indicating that in March of 2016, the president of the World Chess Federation invited the Trump Organization to host, at Trump Tower, the 2016 World Chess Championship Match to be held in New York in November 2016."

"I have also become aware that in November 2016, there were press inquiries to my staff regarding whether I had plans to attend the tournament, which was not being held at Trump Tower," he continued. "I understand these documents have already been provided to you."

Mueller reported that the tournament, which featured a Russian grandmaster chess player and took place just after the 2016 election, was attended by the likes of Dmitry Peskov, Russian President Vladimir Putin's press secretary, and Kirill Dmitriev, CEO of the Russian sovereign wealth fund.

Dmitriev flew to New York for the event and invited George Nader, a Middle Eastern businessman who was questioned by Mueller for meetings with Trump allies, to join him for the opening of the tournament. Nader helped arrange a backchannel meeting between Dmitriev and Blackwater founder Erik Prince, a Trump-ally and brother of Education Secretary Betsy DeVos, which took place in Seychelles.

On the morning of November 9, 2016, Mueller wrote that Dmitriev contacted Nader to request a meeting with "key people" close to Trump "as soon as possible in light of the '[g]reat results'" of Trump's electoral victory. Dmitriev asked Nader "to convey to the incoming Administration that 'we want to start rebuilding the relationship in whatever is a comfortable pace for them.'"

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"Dmitriev invited Nader to the opening of the tournament and noted that, if there was 'a chance to see anyone key from Trump camp,' he 'would love to start building for the future,'" Mueller wrote, adding that Dmitriev "also asked Nader to invite [Jared] Kushner to the event so that [Dmitriev] could meet him."

Nader did not pass along Dmitriev's invitation, Mueller wrote.

Although a World Chess Federation official "recalled hearing from an attendee that President-Elect Trump had stopped by the tournament," Mueller said his investigation "did not establish that Trump or any Campaign or Transition Team official attended the event" and that Trump denied attending in his written answers.

Nader, meanwhile, said Dmitriev "continued to press him to set up a meeting with transition officials" and "was particularly focused on Kushner and [Donald] Trump Jr."

Earlier on November 9, a person whose name was redacted from the report to hide an investigative technique wrote to Dmitriev "Putin has won" after Trump's victory.

Ilya Merenzon, the tournament's organizer, told NBC News in an email that Ilyumzhinov invited the president's business to host the event in his personal capacity, adding that "FIDE and organizers did not have anything to do with it."

Merenzon added: "It's a standard procedure for the World Chess Championship to invite the head of state where the World Chess Championship is held."

Trump was a subject of discussion during the 2016 event, which was also attended by tech entrepreneur and Trump supporter Peter Thiel. In 1995, the last time the chess championship was held in New York City prior to the 2016 tournament, Trump made the ceremonial first move at a qualifying event held in Trump Tower.

In the month before the 2016 election, Trump rankled the American chess community when he wrongly stated that the U.S. has no chess grandmasters, saying that you had to be "a grand chess master" to withdraw the nation from a trade pact "and we don't have any of them."

Trump has been extremely critical of the Mueller report in the days since a redacted version was released by the Justice Department. On Twitter, Trump said the report "was written as nastily as possible" and called it a "total 'hit job' which should never have been allowed to start in the first place!"

At the end of his section on Russian interference and possible collusion, Mueller wrote that while his investigation "established multiple links between Trump Campaign officials and individuals tied to the Russian government," the probe "did not establish that the Campaign coordinated or conspired with the Russian government in its election-interference."