Washington (CNN) In March of last year, a relatively unknown man made his way to the wings of the world stage thanks to a mention by then-candidate Donald Trump.

The real estate mogul and former reality TV star was ratcheting up primary wins and on pace to clinch the Republican presidential nomination. Asked to list members of his foreign policy team in an interview with The Washington Post that March, Trump included "Carter Page, PhD."

Since then, Page has faced questions over his Russia ties -- ties which are getting more attention as Trump's team endures greater scrutiny over interactions with Moscow.

At every turn, Page has rejected the notion that he engaged in any improper action.

During the campaign, he denied there was anything untoward about his visits to Moscow. Since it ended, he has denied specific allegations into his meetings with Russian government and business figures as well as any kind of liaison role between himself and the Trump campaign -- denials the campaign and now the White House have repeated again and again.

No evidence has been made public that links Page to anything improper with regard to Russia and the Trump campaign.

US to Moscow and back

Page is a graduate of the US Naval Academy and New York University's Stern School of Business, according to his company biography . He was also a fellow with the Council on Foreign Relations, and although he's written and lectured on foreign policy, the bulk of his career has been devoted to the business world.

By his own account, Page first visited Moscow in 1991 as the Soviet Union was disintegrating.

"There was a great optimism in the streets about the possibilities for a major change in US-Russia relations," Page recalled in an ABC interview , comparing that time to the attitude he felt in Russia during the 2016 campaign.

Page worked for seven years as an investment banker at Merrill Lynch, which his biography said took him to London, New York and Moscow, where he spent three years, from 2004 to 2007.

Upon his return from Moscow to New York, Page started a firm known as Global Energy Capital LLC, where Politico said his only partner was a former Gazprom executive, Sergei Yatsenko.

A State Department cable made public by WikiLeaks in 2011 said two managing partners from the firm traveled to Turkmenistan in June 2008, trying to get together money for a billion-dollar investment fund. One of the partners, the cable said, claimed to have "helped to take Gazprom from its status in the early 1990s as a national energy company to 'super major' status."

The cable does not name the managing partners outside of saying they were from Global Energy Capital.

The Great Recession started in the US soon after, and Page told Bloomberg that since then he's done quiet deals consulting with people, for example, on how to buy assets in Russia.

Gazprom and Rosneft

Gazprom, the partially state-owned oil enterprise that was once the most valuable company in Russia -- in 2011, it posted one of the best quarters any company has had in history -- has tumbled following declining oil prices and sanctions on the Russian economy.

Page's company biography said he worked with Gazprom, but the nature of his work and the strength of his connections is less clear. He told Bloomberg that when he worked with Merrill Lynch in Moscow, he helped advise the oil giant on one of its largest deals.

He also said US sanctions placed on Russia under President Barack Obama directly hurt his bottom line because of his investments in Gazprom, whose annual investor meetings he said in the Bloomberg interview last March he still attended.

Reuters spoke with three former Merrill Lynch employees who worked in Moscow.

"Page was a vice president at Merrill, a mid-tier banker who was not originating deals," said Sergey Aleksashenko, whom Reuters said had led Merrill Lynch's Moscow operation.

Then-Senate Minority Leader Harry Reid wrote to FBI Director James Comey in August and asked him to investigate Page over, among other things, "conflicts of interest" due to his investments in Gazprom.

In turn, Page wrote a letter to Comey telling him he had divested his stake in the company in August.

But in the world of oil, Gazprom has been overtaken by another Russian enterprise: Rosneft, which has also been burdened by Western sanctions.

Page has denied in repeated interviews any meeting during the campaign with Rosneft President Igor Sechin, although he praised Sechin in an article for Global Policy following the US decision to include Sechin on a sanctions list.

"Sechin has done more to advance US-Russian relations than any individual in or out of government from either side of the Atlantic over the past decade," Page wrote.

In an interview Thursday night with MSNBC's Chris Hayes, Page said he had never met with Sechin "one on one" and "absolutely" had not met with him over the summer during the campaign.

Russian politics

Page has regularly and publicly espoused views at odds with much of the foreign policy community in Washington.

Like Trump, Page has questioned the US approach toward Russia and called for warmer relations between the two countries.

He has spoken out against the US sanctions on Russia over its annexation of Crimea, criticized the EU and NATO's approach to the country and argued that Western scholars had "unnecessarily perpetuated Cold War tendencies by deepening suspicions from that era."

In the Global Policy article, Page chastised the West for focusing on "the so-called annexation of Crimea."

"From US policies toward Russia to Iran to China, sanctimonious expressions of moral superiority stand at the root of many problems seen worldwide today," Page wrote.

In December, he traveled to Russia and held a news conference where, like many others, he questioned the growing claim within the United States that the Russian government had been behind hacks of the Democratic National Committee and Hillary Clinton Campaign Chairman John Podesta.

"It's very easy to make it look like exactly it was (a) country's acts -- in this case Russia that did this," Page said, according to the Russian outlet Sputnik News . "So I think this is very much overestimated until there's serious evidence,"

At the time, the US government had not yet released its intelligence report officially accusing Russia of the breaches, the public version of which provided limited evidence outside of the claims themselves.

However, on October 7, 2016, the US intelligence community said it was confident Russia directed the hacks.

Russia continues to deny any interference in the US election.

The election

Page was largely unknown in the political world until last March, when Trump named him as one of the members of his foreign policy team in the Washington Post interview. CNN later confirmed the name with spokeswoman Hope Hicks.

He traveled to Russia in July, where he gave a lecture and would not answer questions from Reuters about US-Russia policy.

Asked by CNN's Anderson Cooper on Friday if the Trump campaign knew about his trip in advance, Page said, "People knew about it, yeah."

Reports indicated Page was one of several Trump advisers to meet with Russian Ambassador Sergey Kislyak during the Republican National Convention in Cleveland, Ohio.

In his Thursday interview on MSNBC, Page seemed to confirm the meeting by responding to a question: "I do not deny that."

Asked in the same interview about his role within the campaign, Page said, "It's the old first rule of 'Fight Club.' You don't talk about 'Fight Club.' "

He went on to say that he had written memos and listened in on conference calls.

Trump campaign officials were quoted as late as August 24 saying that Page had a relationship with the campaign -- spokeswoman Hope Hicks told Reuters he was an "informal adviser."

Yahoo News reported in late September that US investigators were scrutinizing Page's activity in Russia and his potential connections to influential Russians. That's when the Trump campaign started denying a relationship with Page.

Jason Miller, the Trump campaign's communications director, told The Hill that Page had "never been a part of (the) campaign," and Kellyanne Conway said on CNN's State of the Union that Page was "certainly not part of the campaign that I'm running."

Page told CNN's Anderson Cooper that he had never met Miller and refuted Miller's comment that he hadn't been a part of the campaign.

"Jason didn't know," Page said.

Conway only started running the campaign partway through the race, when Trump brought her and Steve Bannon in following the exit of campaign manager Paul Manafort.

Shortly after, Page announced that he was taking a "leave of absence" from the Trump campaign.

CNN reported in early November that the FBI was conducting multiple investigations into connections between the Trump campaign and Russia, which law enforcement officials said at the time had so far yielded little. Page told CNN he blamed Democrats.

Page has said he sent policy memos to the campaign and participated in conference calls as well as gatherings that included Trump, but also said he never personally briefed Trump or was in "small meetings" with him during the election. But Trump said last month at a White House news conference that he doesn't think he ever met Page.

"I don't think I've ever spoken to him," Trump said. "I don't think I've ever met him. And he actually said he was a very low-level member of I think a committee for a short period of time. I don't think I ever met him. Now, it's possible that I walked into a room and he was sitting there, but I don't think I ever met him."

Page told CNN he had never shaken Trump's hand and that by saying he had met with Trump, he had meant meetings in the "Russian sense," which he said meant he had attended rallies Trump spoke at.

In February, Page released a letter he sent to the Department of Justice asking the law enforcement branch to look into "election fraud," "hate crimes" and other misdeeds from the Clinton campaign and its allies.