Donald Trump Jr. stayed out of his father’s Washington to run the family business, but he keeps getting drawn back into special counsel Robert Mueller’s investigation into the 2016 presidential campaign

Trump Jr. was at the center of an infamous June 2016 Trump Tower meeting with a Russian lawyer offering dirt on Hillary Clinton. Now, a new revelation places the younger Trump in another meeting in the Manhattan tower with a business executive offering potentially illegal assistance from the crown princes of Saudi Arabia and the United Arab Emirates for Donald Trump’s presidential campaign.

Other participants in the newly disclosed meeting in August 2016 were an Israeli social media specialist and the former head of the Blackwater private security firm, who helped arrange the meeting, according to a report in the New York Times.

It’s unclear whether either meeting resulted in assistance actually being provided to the campaign. But taken together, the encounters show Trump Jr. actively exploring whether foreigners could help his father’s candidacy, even though it’s illegal for foreign citizens to contribute to U.S. campaigns.

Trump Jr. has emerged as a popular salesman for his father’s presidency — a New York City businessman who can bring in the crowds for GOP fundraisers. But new suggestions that Trump Jr. may be in Mueller’s cross-hairs provoked a furious reaction from Trump on Sunday.

“Things are really getting ridiculous,” the president wrote on Twitter. “The Failing and Crooked (but not as Crooked as Hillary Clinton) @nytimes has done a long & boring story indicating that the World’s most expensive Witch Hunt has found nothing on Russia & me so now they are looking at the rest of the World!”

Alan Futerfas, Trump Jr.’s lawyer, acknowledged in a statement that the meeting was held but said an elaborate social media strategy pitched to Trump Jr. was rejected. Trump Jr. and his allies don’t see the new revelations as significant because the meeting didn’t result in a contract or work with the campaign, according to a person familiar with the details.

But the top Democrat on the Senate Intelligence Committee, Mark Warner of Virginia, said Sunday that the meeting demonstrates a pattern of other nations trying to interfere in the U.S. election.

“If the Times story is accurate and there is this pattern that other countries were offering, and clearly, the Trump campaign was receptive to these kinds of offers, how is that not the beginnings of evidence of stuff that needs to be investigated?” he said on CNN.

Futerfas said George Nader, a Lebanese-American businessman, was at the meeting with Trump Jr. The Times reported that Nader told Trump Jr. “that the crown princes who led Saudi Arabia and the United Arab Emirates were eager to help his father win election as president.”

The other attendees were Joel Zamel, an Israeli and social media specialist, who presented “a multi-million dollar proposal,” for an effort to help Trump, and GOP donor Erik Prince — a former Navy SEAL, brother of current Education Secretary Betsy DeVos and founder of the controversial private security firm Blackwater — who arranged the meeting, according to the Times.

Mueller is looking into the interactions and questioning people about that Trump Tower meeting, the newspaper said.

“They pitched Mr. Trump Jr. on a social media platform or marketing strategy,” Futerfas said in a statement. “He wasn’t interested and that was the end of it.”

Former New York Mayor Rudy Giuliani, one of Trump’s lawyers, said Sunday in an interview that he expects to talk to Mueller’s team early this week.

New details also emerged last week about the June meeting with the Russian lawyer and her representatives. Transcripts released by the Senate Judiciary Committee portrayed Trump Jr. as leading the meeting and being actively interested in the damaging information on Clinton that a meeting organizer had promised.

“He was definitely in charge,” Rinat Akhmetshin, a lobbyist and former Soviet counterintelligence officer, recalled. After small talk about the view and a recent win in the primaries, the younger Trump got down to business, Akhmetshin said. “Mr. Trump, Jr., said, ‘So I believe you have some information for us.’ “

But Akhmetshin said Natalia Veselnitskaya, the Kremlin-linked Russian lawyer at the center of the meeting, ultimately didn’t have proof of wrongdoing related to Clinton.

Senate Judiciary investigators didn’t ask about the meeting with Prince and Nader. And Prince, in a separate interview with the House Intelligence Committee, denied having formal contacts with the Trump campaign, an assertion that could get new scrutiny in the wake of the Times report.

Read more: Transcript of Trump’s interview with House Intelligence Committee

Democrats also noted that there were dozens of times when Trump Jr. told congressional investigators he couldn’t recall details of discussions or events during his testimony from Sept. 7, 2017.

In his testimony, Trump Jr. denied working with foreign governments during the campaign. “I did not collude with any foreign government and do not know of anyone who did,” he said.

He also dismissed a question about whether support from Russia would be “problematic.”

“I didn’t think that listening to someone with information relevant to the fitness and character of a presidential candidate would be an issue, no,” he said.

The Senate Intelligence Committee is continuing its probe of Russian election collusion, according to Warner, and he wouldn’t say Sunday whether its investigators were previously aware of the second meeting with representatives of Gulf state nations, or if their offer of help for the campaign was followed through.

He did say the latest report provides some new information as they continue to look into U.S. election interference.