When Elias Demetracopoulos died in Athens in 2016 at 87, The Washington Post described him as an “ ‘enigmatic’ expatriate.” In its obituary, the New York Times chose similar language, calling him an “enigmatic journalist.”

The man had been so many things, and accused of being many more, that it was difficult to sum up his story. Journalist, Nazi resistance fighter and Wall Street consultant were among his callings; spy, egotist and “dangerous gadfly” were among the accusations. His life was so complicated it was hard to tell where one version of Demetracopoulos ended and another began.

In “The Greek Connection,” James H. Barron seeks to put the pieces together — but the Demetracopoulos puzzle was not the one he originally set out to solve. Barron was researching allegations of a transfer of funds from Greece’s intelligence agency to Richard Nixon’s 1968 presidential campaign, which he believed formed an underexplored chapter of Watergate. During a chance encounter with Seymour Hersh, the investigative journalist suggested that Barron contact Demetracopoulos, a Greek expatriate living in Washington who once tried to expose the money scheme. “I quickly realized,” Barron writes, “that this episode was but part of Elias’s much larger and even more compelling life story.” A biography was born.

Barron, a journalist and lawyer, delivers a richly sourced work. He spoke with Demetracopoulos for five years, sometimes daily, until his death in 2016. He gained access to Demetracopoulos’s personal papers and government records, and interviewed those who had known him both in his native Greece, which he fled after a 1967 military coup, and in Washington, his adopted home until his final months.

The story that emerges is at times cinematic, starting with a moving account of 12-year-old Elias’s resistance efforts during the Nazi occupation of Athens. The boy was imprisoned, beaten and moved to an asylum before being released. Later, stricken with tuberculosis and homebound, Demetracopoulos relied on newspapers as a link to the outside world and as the source of a possible career. “He didn’t want to be a doctor, lawyer, businessman, or engineer. He wanted to be a journalist,” Barron writes. “He also reckoned that, if he did it well, he could even be more famous than the people he covered. He wanted to make news by getting news.”

Demetracopoulos, while reporting for a series of Greek and American newspapers, cultivated connections to powerful figures, regularly blurring journalistic boundaries. Once, following an interview with Cuban leader Fidel Castro’s brother, Raúl, at the Cuban Embassy in Athens, Demetracopoulos got the Cubans to transcribe the interview and Raúl to sign each page. Then he called the U.S. Information Service to convey “inside information,” including his own impressions of the Castro entourage.

Demetracopoulos seemed to acquire sources and detractors in equal measure. He would spend decades combating CIA, FBI and State Department reports that maligned and discredited him. The list of countries alleged but never proved to have hired him as a spy included Israel, the Soviet Union, the United States and Greece. More than once, government officials pressured newspapers into severing ties with him.

Demetracopoulos specialized in exclusive interviews with government officials and fancied the nickname “the Scooper.” But a desire for political influence seduced him and ultimately undercuts the author’s claims for him as a model for modern journalists. Barron recounts that as a young reporter, Demetracopoulos obtained a secret memorandum discussing the overthrow of the Greek government. “Rather than writing about it,” the author reports, “he quietly showed his copy of the memo to the American political-affairs counselor.”

This tension between journalism and activism sits at the heart of the book’s inquiry into a corner of the Watergate story. Demetracopoulos undertook his investigation of Nixon’s financial misconduct with Greece after fleeing his homeland for Washington in the wake of the military junta’s takeover. He decided it was “time to join the resistance,” but not within Greece. “He wanted to fight to restore democracy from outside his country,” Barron writes.

In the United States, Demetracopoulos began working as a Wall Street political adviser with a growing reputation as a bon vivant who “dated omnivorously.” When Nixon’s 1968 running mate, Spiro Agnew, made a surprise endorsement of the Greek junta, Demetracopoulos suspected dark motives and started contacting sources. The story he pieced together was explosive: He laid out a tale of the military dictatorship secretly funneling $549,000 to the Nixon campaign in a drachma-to-dollars transfer that probably included CIA black-budget money.

Rather than informing reporters, Demetracopoulos sought a path to President Lyndon Johnson. He shared his findings with Larry O'Brien, Democratic Party chairman and campaign manager for presidential nominee Hubert Humphrey. Demetracopoulos's hope that Johnson would urgently confirm the story with the CIA and then leak it (the election was less than three weeks away) proved naive. The would-be Nixon scandal was a "stillborn October Surprise."

The scandal outlined by Demetracopoulos’s sources lacked incontrovertible evidence, and it’s painful to read of his reliance on the Humphrey campaign to prove it. Why didn’t Demetracopoulos take his story elsewhere, including to U.S. journalists with whom he had relationships? An answer is elusive. All Barron can say is, “Not doing so was a fatal miscalculation.”

“Was my information accurate?” Demetracopoulos would later write in The Post in 1997. “The campaign of intimidation that the Nixon White House subsequently launched against me convinced me that I wasn’t wrong.” It wasn’t until Nixon had left the White House that firmer evidence emerged, what even Demetracopoulos called “more definitive corroboration.” This included Hersh’s reporting that a former U.S. ambassador to Greece gave secret House testimony about the transfer of funds from the junta to Nixon’s reelection coffers.

For the rest of his life, Demetracopoulos nursed his disappointment over his lost chance for a place in history. In the book Barron plays out the woulda-coulda imaginings about a world where the blockbuster allegations were made public. In that scenario, the story costs Nixon the election and there is no Watergate. Instead of Woodward and Bernstein, the reporters who break the story of the junta’s illegal payments become journalistic icons. And Elias Demetracopoulos, not Daniel Ellsberg, is the “international poster boy for whistleblowers.”

“The Greek Connection” opens with the words: “He was a journalist before he was a journalist. A gatherer and disseminator of information, he never considered doing anything else.” But ultimately Demetracopoulos was something more complex, though that something was, as the obituaries would say, an enigma.

Barron writes that Demetracopoulos was fearful of being forgotten. This volume is an ambitious effort to forestall that, even if we’re not entirely certain who it is we’re remembering.

The Greek Connection

The Life of Elias Demetracopoulos and the Untold Story of Watergate

By James H. Barron

Melville House. 482 pp. $32.99