In August 2016, a private jet linked to Russian oligarch Oleg Deripaska traveled from Moscow to Newark Liberty International Airport in Newark, New Jersey. The Gulfstream G550 (registration M-ALAY) landed shortly after midnight and, according to publicly available flight records, flew back to Moscow that same afternoon. Deripaska, 50, is the founder of Basic Element, a Russian industrial conglomerate with massive holdings in aluminum, energy, and construction. With an estimated net worth of $6 billion, he can afford to send a private jet across the globe whenever he wants.

Still, according to a source familiar with the matter, that August flight has caught the attention of congressional investigators, in part because of its timing.

The jet arrived within hours of a meeting in nearby Manhattan between Paul Manafort, then chairman of Donald Trump’s presidential campaign, and Konstantin Kilimnik. Kilimnik spent over a decade as Manafort’s translator and fixer in Ukraine. Weeks earlier, Manafort had emailed his old associate and told him to extend an offer of "private briefings" to Deripaska, according to The Washington Post.

Congressional investigators looking into Russian meddling in the 2016 election are now probing the relationship between Manafort, Kilimnik, and Deripaska, according to two people familiar with the matter. The jet’s brief trip to New Jersey raises fresh questions about the relationship between the three men during the 2016 presidential campaign. Deripaska is believed to have close ties with the Kremlin. Kilimnik has been widely reported to be the unnamed person identified in court filings by special counsel Robert Mueller's office this week as having ties to Russian intelligence — a relationship Kilimnik has long denied.

Manafort has since been named in a 32-count indictment by Mueller’s team on charges including bank fraud and filing false tax returns related to his work for the former government of Ukraine.

A spokesperson for Deripaska confirmed the Gulfstream jet’s flight to New Jersey to VICE News, but said the trip had nothing to do with Manafort’s offer of briefings, which the spokesperson said Deripaska never received. “The passengers of the flights during the time period in early August 2016 were Mr. Deripaska’s family only,” the spokesperson, who asked not to be named, wrote in an email to VICE News. “As it was previously stated, Mr. Deripaska had no communications, meetings, briefings, or other interaction with Mr. Manafort during, after, or in the run-up to the 2016 Presidential Election. Thus, we repeat that any publications implying that Mr. Deripaska directly or indirectly communicated with Mr. Manafort in 2016 would be a false statement of fact.”

“Person A has ties to a Russian intelligence service ”

On Tuesday night, prosecutors working for Mueller released a court filing saying that an unnamed associate of Manafort’s “has ties to a Russian intelligence service and had such ties in 2016.” According to the filing, Rick Gates, who held various senior positions in the Trump campaign and was Manafort’s longtime business partner, said the associate “was a former Russian Intelligence Officer with the GRU,” Russia’s military intelligence agency. The associate, referred to simply as “Person A,” isn’t identified, but the detailed description provided by prosecutors lines up closely with Konstantin Kilimnik.

Kilimnik didn’t respond to emailed requests for comment, and two people who know him, including a reporter in Ukraine who was in touch with Kilimnik in 2017, told VICE News that he has stopped responding to requests for interviews in recent months. Yet Kilimnik is known to have been in direct email contact with Manafort as recently as late November 2017, according to court filings by Mueller’s team. Gates had repeated contacts with “Person A” during the final weeks of the 2016 campaign, according to the special counsel filing. In February, Gates pleaded guilty to charges of conspiracy and lying to the FBI, and struck a deal to cooperate with Mueller’s ongoing investigation.

Peter Carr, spokesman for the special counsel’s office, declined to comment to VICE News for this story.

In the past, Kilimnik has strenuously denied any link to Russian intelligence, once telling The Washington Post, in a statement relayed by Manafort’s attorney, that although he did serve as a Russian military translator in the early 1990s, he has “no relation to the Russian or any other intelligence service.”

People who know Kilimnik describe him as highly intelligent and a smooth operator who speaks good English and Swedish, and they say he’s very well connected in Ukrainian and Russian political and business circles. Those sources say he’s been on good terms with the staff of the U.S. embassy in Kiev.

Manafort’s “right hand… in Kiev”

A former Ukrainian government official who has known both Manafort and Kilimnik for years described Kilimnik to VICE News as Manafort’s “right hand… in Kiev.” He said Kilimnik “translated for him [Manafort] at all high-level meetings.”

The former official continued: “I know that Kilimnik used to be a welcome guest in [the] U.S. embassy, and no one then evidently suspected him of being a Russian spy.” American diplomats and foreign policy officials confirmed that Kilimnik was a familiar presence in American diplomatic circles.

According to a story in Politico last year, after he returned from meeting Manafort in Manhattan in August 2016, Kilimnik suggested to an unnamed associate in Ukraine that he had helped remove language from the Republican Party platform that would have laid out a tougher stance toward Russia.

A proposed amendment called for the U.S. to provide “lethal defensive weapons” for Ukraine to defend itself against Russia. Mueller’s team is now probing how the phrase came to be removed from the platform in July 2016 at the Republican National Convention, according to Reuters.

“He led me to believe that he was involved in the platform fight, but not necessarily through Paul,” a Kiev-based operative, described as someone who “travels in the same circles” as Kilimnik, told Politico. But the person added that Kilimnik could have been “just bullshitting like political consultants do.”

“Provided that he buys me a ticket”

On July 7, 2016, months after he joined the Trump campaign, Manafort emailed Kilimnik with a message to pass on to Deripaska. Years earlier, Manafort provided Deripaska with investment and consulting services before their business relationship soured. In January, a company controlled and funded by Deripaska sued Manafort and Gates for at least $25 million in damages connected to a failed joint cable and internet venture in Ukraine, according to court documents.

“Tell V boss that if he needs private briefings, we can accommodate,” Manafort told Kilimnik, according to an exchange reported in The Atlantic. According to that report, “V” was an aide to Deripaska named Victor.

Manafort’s spokesman, Jason Maloni, has confirmed that the reported emails between Manafort and Kilimnik are legitimate. But he’s called the email exchange “innocuous,” and said that the briefings never occurred.

On July 29, Kilimnik sent an email to Manafort with the subject line “Black Caviar” proposing the two men meet in person. Kilimnik wrote that he had “important messages” to deliver to Manafort from an unnamed person, “provided that he buys me a ticket.”

“I met today with the guy who gave you your biggest black caviar jar several years ago,” Kilimnik wrote, according to The Atlantic report. “We spent about 5 hours talking about his story, and I have several important messages from him to you. He asked me to go and brief you on our conversation. I said I have to run it by you first, but in principle I am prepared to do it, provided that he buys me a ticket. It has to do about the future of his country, and is quite interesting. So, if you are not absolutely against the concept, please let me know which dates/places will work, even next week, and I could come and see you.”

Manafort reportedly wrote back: “Tuesday is best.”

The next Tuesday was August 2.

Previous press reports have given the date of Manafort and Kilimnik’s meeting in Manhattan’s Grand Havana Room cigar club as August 2, or "about two weeks before Manafort resigned" from the Trump campaign, which happened on August 19. Sources who spoke to VICE News have not been able to confirm the exact date of the meeting in early August 2016.

The private Gulfstream jet that landed in Newark after midnight on August 3 has been previously linked to Deripaska by Russian opposition leader Alexei Navalny in an investigative video released in February. That video purports to show Deripaska meeting with a high-level Russian government official on a yacht off the coast of Norway within days of the plane’s return to Moscow. Deripaska has dismissed the video’s claims as “false” and “outrageous,” and “the result of a planned campaign aiming to damage my reputation.”

The spokesperson for Deripaska confirmed the plane’s flights in August 2016 but didn’t respond to emailed questions from VICE News about whether the billionaire actually owns the plane. In the documentary, Navalny tracks the jet, and uses Instagram posts and other publicly available information to present evidence of what he claims was a meeting between Deripaska and Russian deputy prime minister Sergei Prikhodko on a yacht off the Norwegian coast on the weekend after flight records show the jet returned from Newark.

The fact that the M-ALAY jet made a brief trip to New Jersey in early August 2016 was pointed out in a Medium blog post by a young independent journalist and UC Irvine senior named Scott Stedman in early March, and then picked up by independent Russia-focused outlet The Bell.

Both Manafort and Kilimnik have denied that their discussion in early August was directly related to the upcoming U.S. election. In June 2017, Kilimnik told the Post that he and Manafort discussed “unpaid bills” and “current news,” and that their talk was “in no way related to politics or the presidential campaign in the U.S.”

Maloni, Manafort’s spokesman, has said that “it would be neither surprising nor suspicious that two political consultants would chat about the political news of the day, including the DNC hack, which was in the news.”

Maloni declined to comment on the record to VICE News for this story.

In text messages with a reporter for Radio Free Liberty/Radio Europe last fall, Kilimnik said his conversations with Manafort over the many years they worked together had been wide-ranging.

"There were millions of emails. [...] we worked for 11 years. And we discussed a lot of issues, from Putin to women," Kilimnik reportedly wrote. "Of course we discussed Trump and everything," he said in another message.

In those texts, Kilimnik went on to deny any links to Russian intelligence. And Kilimnik worried about the fate of his longtime acquaintance Manafort as Mueller’s investigation into Russia’s involvement in the election closed in on him.