Carter Page, a onetime adviser to Donald Trump. Sergei Karpukhin/Reuters Associates of President Donald Trump have worked hard to distance themselves from Carter Page, an investment banker turned foreign-policy adviser whose ties to Russia have fueled speculation that the Trump campaign may have colluded with Moscow to undermine Hillary Clinton during the election.

But the campaign's descriptions of Page's role, including how he got it and how long he served in it, have varied and in some cases contradicted one another. The conflicting explanations have raised questions about why no one seems to know for sure, or at least isn't willing to say, who brought Page on — and why.

Page's personal and professional history offers little hint of an interest in American politics or foreign policy, except for a yearlong stint at the Council on Foreign Relations in the late '90s.

He also wrote occasional blog posts between 2013 and 2014 in which he criticized the US sanctions on Russia as "sanctimonious expressions of moral superiority" and praised Igor Sechin, the executive chairman of Russia's state oil company, Rosneft, for his "accomplishments" in advancing US-Russia relations.

Page lived in Moscow in the early 2000s, when he was an investment banker for Merrill Lynch. He says he has served as an adviser "on key transactions" for Russia's state-owned energy giant, Gazprom. In 2011, Page set up his investment fund, Global Energy Capital, with former Gazprom executive Sergey Yatesenko.

On March 21, 2016, Trump named Page a member of his foreign-policy team in an interview with The Washington Post, prompting questions about how an energy consultant with no foreign-policy experience landed on Trump's radar. The Daily Caller reported recently that Corey Lewandowski, Trump's first campaign manager, recruited Page to the campaign. Other reports say that Sam Clovis, a campaign co-chair, brought him on.

Page served in the Navy for five years after graduating from the Naval Academy in 1993. He drove a Mercedes and "reveled in lavish spending that sometimes seemed to exceed his means," The New York Times reported on Wednesday.

Page told The Times last month that "the half year I spent on the Trump campaign meant more to me than the five years I spent in the Navy." But the extent of his involvement with the campaign is even murkier than how he landed on it.

Sergey Kislyak, the Russian ambassador to the US. Getty Mario Tama

Page said early last month that he "spent many hours" at Trump campaign headquarters last year, referring to himself in a letter to the Senate Intelligence Committee as a "campaign surrogate." An administration official who worked with the campaign told Business Insider at the time, however, that no one could recall having seen Page at Trump Tower, where the campaign was headquartered.

But a campaign adviser recently told The Post that Page "was one of the more active" foreign-policy advisers on a team that included terrorism analyst Walid Phares, former Pentagon inspector general Joseph Schmitz, international energy lawyer George Papadopoulos, and retired Army Lt. Gen. Joseph Keith Kellogg.

The adviser told The Post that Page frequently submitted policy recommendations and requested meetings with Trump, which the campaign has said were never granted. He attended three dinners held for the foreign-policy advisers in the spring and summer of 2016, according to The Post, and met Russia's ambassador to the US, Sergey Kislyak, at the Republican National Convention in July.

Page evidently was still meeting with the foreign-policy group as late as August 19, Phares told Reuters at the time.

In September, Yahoo's Michael Isikoff, citing a Western intelligence source, reported that Page traveled to Moscow in July — a trip that Politico reported was approved by Lewandowski — to meet with Sechin.

Page has denied those reports, insisting he was there only to give a speech at Moscow's New Economic School. But the trip raised red flags at the FBI, which sought and obtained an order under the Foreign Intelligence Surveillance Act to surveil Page's communications shortly thereafter. He is the first — and, so far, only — member of Trump's campaign to have been placed under direct FBI surveillance as a result of his ties to Russia.

Trump and his first campaign manager, Corey Lewandowski. AP Photo/Charlie Neibergall

Page told Business Insider recently that he thought the FISA requests were "unjustified." But the government's application for the FISA order has been renewed more than once, according to The Post.

The Trump campaign scrambled to distance itself from Page in September. Jason Miller, its communications director, told The Hill on September 24 that Page had "never been a part of our campaign." Campaign manager Kellyanne Conway told CNN a day later that Page was "certainly not part of the campaign that I'm running."

But Lewandowski — who was, at least officially, the highest-ranking campaign official until June — told Reuters in August that Page had "definitely" been an adviser.

(The current administration official who worked with the campaign and spoke to Business Insider last month said Miller and Conway had never met Page and that was why they downplayed his role on the campaign.)

Page took a "leave of absence" from the campaign in September after news broke of his July trip to Moscow. In a letter to the Department of Justice in February, Page said he had "decided to step back" from the campaign so he could "more effectively fight" allegations that he had inappropriate contact with the Russians, "and not create a further distraction for my colleagues."

BuzzFeed had one month earlier published a 35-page dossier detailing Trump's alleged ties to Russia that, among other things, accused Page of serving as a liaison between the Trump campaign and Moscow during the election.

The document appeared to corroborate what Yahoo reported four months earlier — Page took his controversial trip to Moscow, it said, to meet with Sechin. There, Page was offered the brokerage of a 19% stake in Rosneft in exchange for the lifting of US sanctions on Russia, but was noncommittal, according to the dossier.

On December 7, Rosneft signed a deal to sell 19.5% of its shares, roughly $11 billion, to the multinational commodity trader Glencore Plc and Qatar's state-owned wealth fund. Qatar's sovereign wealth fund is Glencore's largest shareholder.

Page was in Moscow on December 8 to "meet with some of the top managers" of Rosneft, he told reporters at the time. He denied meeting with Sechin during that trip but said it would have been "a great honor."

The FBI used the dossier's raw intelligence about Page to bolster its case for the FISA order, according to CNN, indicating the bureau had enough confidence in the validity of the document to corroborate it and present those findings in court. The fact that Page was already on the FBI's radar because of his ties to a Russian spy who posed as a UN attaché in New York City in 2013 may have further helped the bureau's case.

"In my long experience in dealing with FISA processing, unconfirmed information about a potential target cannot and has not been included in the application," said John Rizzo, the former acting general counsel of the CIA. "So if the CNN report is accurate, then I have to believe that the FBI and Department of Justice concluded, and the court agreed, that the info in the dossier about Page was reliable."