Portland running coach Alberto Salazar was banned from the sport for four years on Monday after the U.S. Anti-Doping Agency ruled he had violated rules against performance-enhancing drugs, ProPublica reported.

Salazar is a prominent figure in Oregon athletics—he runs Nike's Oregon Project and coaches some of the most successful long-distance runners in the world. Allegations that Salazar had alleging been giving his athletes performance-enhancing drugs have been brewing since 2015. And in 2017, the USADA released a 269-page report examing detailed allegations.

Salazar is accused of breaking three anti-doping rules—including that he administered drugs in a prohibited matter, tried to tamper with the doping control process and trafficked testosterone.

Salazar said in a public statement that he plans to appeal the ruling and that he was "shocked by the outcome."

"Throughout this six-year investigation my athletes and I have endured unjust, unethical and highly damaging treatment from USADA," he said. "The Oregon Project has never and will never permit doping. I will appeal and look forward to this unfair and protracted process reaching the conclusion I know to be true."

Nike adds in a statement that Monday's decision from the USADA "had nothing to do with administering banned substances to any Oregon Project athlete."

It continued: "We support Alberto in his decision to appeal and wish him the full measure of due process that the rules require. Nike does not condone the use of banned substances in any manner."

Read ProPublica's full report on the USADA's findings against Salazar here.