Carter Page, a former adviser to then-candidate Donald Trump, speaks at the graduation ceremony for the New Economic School in Moscow on July 8. (Pavel Golovkin/AP)

Carter Page, who served briefly as a foreign policy adviser to Donald Trump’s presidential campaign, made an appearance in a federal espionage case because he communicated several years ago with a Russian intelligence agent under surveillance by the FBI.

In a statement released Tuesday, Page confirmed his role in the 2015 Justice Department spy case, adding another twist to the still-unfolding story of Trump’s peculiar and expanding ties to people connected to Russia.

Page said he assisted U.S. prosecutors in their case against Evgeny Buryakov, an undercover Kremlin agent then posing as a bank executive in New York. Buryakov was convicted of espionage and released from federal prison last week, a few months short of completing a 30-month sentence. Buryakov agreed to be immediately deported to Russia.

Page’s involvement was first disclosed Monday by BuzzFeed, which said Page was identified as “Male 1” in the Justice Department’s complaint against a Russian spy network based in New York.

In a written exchange with The Washington Post, Page confirmed playing a role in the case but declined to discuss details.

Evgeny Buryakov sits in court in New York on Jan. 26, 2015. Former Trump campaign adviser Carter Page played a role in the espionage case against Buryakov. (Jane Rosenburg/Reuters)

“Given the very light masking in the original document from January 2015, you can draw your own conclusions,” Page wrote.

According to the court records, the FBI interviewed Page as part of the case against three Russian men identified as agents of the Russian overseas intelligence agency, the SVR. One of them, Buryakov, was operating undercover as an executive in the New York office of a Russian development bank, Vnesheconombank.

The case resurfaced in news accounts last week when President Trump’s adviser and son-in-law, Jared Kushner, acknowledged he had met with the head of the same bank in December.

The complaint includes transcripts from 2013 of wiretapped conversations among the Russians discussing their efforts to recruit Male 1, identified as a New York energy trader whom the Russians described as willing to talk.

In his statement, Page compared the revelation of his role to “the politically-motivated unmasking standards seen in the Obama Administration which have recently been exposed.”

He said the information was released as “retribution for my public positions of dissent” against Obama administration policy toward Russia. The information about his role in the case “amplified the reputational damage against me” that has occurred through 2016, Page said. After he was named by Trump as a foreign policy adviser, news reports discussed his travel to Russia and his frequent criticism of U.S. policy toward Russia under Obama.

According to the 2015 complaint filed in federal court in the Southern District of New York, Page met with a Russian agent, Victor Podobnyy, in January 2013 at an energy conference in New York. It says that from January to June of that year, Page as Male 1 “provided documents to [Podobnyy] about the energy business.” At the time, the Russians were seeking information on U.S. sanctions and on energy development.

Although Page communicated with the Russian agents in 2013, he said the information he provided was innocuous.

“As I explained to federal authorities prior to the January 2015 filing of this case, I shared basic immaterial information and publicly available research documents” with the spy who was serving then as a junior attache at the Permanent Mission of the Russian Federation to the United Nations.

“In doing so, I provided him nothing more than a few samples from the far more detailed lectures I was preparing at the time for the students in my Spring 2013 semester ‘Energy and the World: Politics, Markets and Technology’ course which I taught on Saturdays at New York University.”

During an interview with The Washington Post editorial page staff in March 2016, Trump identified Page, once a Merrill Lynch investment banker in Moscow, as a foreign policy adviser to his campaign.

But in January, after Page’s name came up in news reports about Trump administration ties to Russia, Trump press secretary Sean Spicer declared that “Carter Page is an individual the president-elect does not know.”

Page, a longtime energy executive, is a U.S. Naval Academy graduate who rose through the ranks at Merrill Lynch before founding his current firm, Global Energy Capital. He previously was a fellow at the Council on Foreign Relations, where he focused on the Caspian Sea region and economic development in former Soviet states. He is also a fellow at the Center for National Policy in Washington and has a PhD from the University of London.

He made a speech in Moscow in July that included some criticism of U.S. policy.

The White House has energetically rejected the idea that Trump or his allies coordinated with Russia during the election. The president has said investigators and the public should focus instead on leaks of information and reports that he and his advisers were improperly surveilled by the Obama administration.

“The real story turns out to be SURVEILLANCE and LEAKING! Find the leakers,” Trump tweeted Monday morning.

Page has said repeatedly in recent weeks that he would like to tell his story to congressional investigators looking at Russian government efforts to influence the course of the 2016 election and the leak of information about that effort.

“I very much look forward to providing further evidence regarding last year’s historic crimes committed against me and all Americans,” Page said.