A Russian physician of Jewish descent who for decades has been illegally doping athletes is one of the central figures in the scandal that led to the partial ban on Russia in the Rio Olympics, the New York Times reported.

The report Saturday on Dr. Sergei Portugalov was based in part on a document from 1983 that he signed when he was still chief medical doctor for the track and field Olympic delegation of the Soviet Union. Obtained by the Times, the document, which is marked as confidential, has Portugalov urging the team’s head to inject athletes with three anabolic steroids in addition to a banned, orally administered enhancing substance.

Intrigued by Portugalov’s unusual last name, a writer for the Lisbon-based Observador news site investigated his family’s history, the publication reported Sunday. The writer, Jose Milhazes, learned that Portugalov is of Portuguese Jewish descent and that his family chose for itself the name Portugalov in the 19th century when Russian citizens were obligated to adopt a family name as per a decree by the Russian emperor Alexander I.

The World Anti-Doping Agency named Portugalov last year as a key broker of performance-enhancing drugs in Russia, “someone who in recent years injected athletes personally and made a business of covering up drug violations in exchange for money.”

The alleged doping of Russian athletes led the International Olympic Committee to ban most members of the country’s track and field delegation from participating in the 2016 Olympics, which began Aug. 3 and are scheduled to end Monday.

Russian officials and athletes have decried the accusations and ban as politically motivated.