According to Kathimerini, however, the new documents show that Kokkalis continued to report to the spy agency under the code names “Kaskade” and “Krokus” until the fall of Berlin Wall in 1989.

The paper reported that Greek prosecutors are considering these documents in an ongoing investigation of the wealthy entrepreneur.

Kokkalis has responded to these allegations in a statement posted on the website of his telecommunications firm, Intracom. Entitled “A Reply to the Slanderers,” the statement denies all allegations and says that Kathimerini has published similar allegations in the past which have been disproven.

“The independent Greek Justice system has always, after thorough investigations of every item of the so-called indisputable evidence and disclosure, ascertained that all ‘charges’ were and are groundless,” wrote Kokkalis.“The arrogant slanderers who launch such malicious attacks should become well aware that, eventually, their attempts would receive a fitting reply.”

In a statement, Piper Rudnick—a law firm which represents Intracom in the U.S.—emphasized that no indictments have been brought against Kokkalis.

The Greek legal system requires prosecutors to investigate all criminal allegations, whether supported by evidence or not, the statement said.

The firm’s statement quoted a State Department report which called the Greek press “usually aggressive, sensationalist, and frequently irresponsible with regard to content.”

Kokkalis was raised in East Germany, and attended Lemonosov University in Moscow. In 1977, he founded Intracom in Greece.

At age 64, Kokkalis remains chair and chief executive officer of the company. He is also owner and president of Greece’s best-known soccer team, Olympiakos.

In 2001, Forbes magazine valued Kokkalis’s fortune at $1.2 billion, making him the third richest person in Greece at that time.

—Staff writer Nathaniel A. Smith can be reached at nsmith@fas.harvard.edu.