Sir Mo Farah's former coach Alberto Salazar tried "every tactic" to avoid "exposure of the truth", according to United States Anti-Doping Agency (USADA) chief executive Travis Tygart.
Salazar, 61, was banned from athletics for four years along with endocrinologist Jeffrey Brown for "orchestrating and facilitating prohibited doping conduct" while working with the Nike Oregon Project, following a four-year investigation by USADA.
Salazar's violations included "administration of a prohibited method", tampering or attempted tampering with athletes' doping control processes and trafficking or attempted trafficking of testosterone.
Salazar confirmed he intends to appeal the ban after describing the investigation as "unjust, unethical and highly damaging", but Tygart has welcomed the decision to sanction the American coach.
"They went through a full on legal battle, frankly, where they tried every tactic to avoid the exposure of the truth," Tygart told Sky Sports News.
"You have to understand this was not a USADA decision, this was independent triple A (American Arbitration Association) arbitrators, who heard all the evidence.
"They listened to the witnesses, looked at the documents and came to the conclusion that they came to. The process, as in every case, is ultimately very fair.
"Coach Salazar and Dr Brown had every opportunity to confront the witnesses, challenge the evidence and make their arguments in front of the independent judges.
"The independent judges' decision was that they violated the anti-doping rules, they were serious violations and that they ought to be held accountable for those."
The Nike Oregon Project was home to four-time Olympic champion Farah from 2011 to 2017, before he parted ways with Salazar.
Farah said in a statement that he has "no tolerance for anyone who breaks the rules or crosses a line" regarding doping.
Tygart confirmed USADA's investigation was aided by some of Salazar's former athletes.
"We got great cooperation and participation from a number of athletes from around the world who sat down with us, gave us access not only to their medical records but also voluntarily answered questions under oath which we found to be very truthful," added Tygart.
"They were part of the hearing where it was relevant to the charges that we brought against Coach Salazar and Dr Brown."
Tygart believes Salazar's ban will act as a "strong deterrent" for other coaches considering doping violations.
He said: "Whether you're a high profile coach or just a weekend warrior that nobody has ever heard of, our job at USADA and all independent organisations around the world, like UKAD for example, is to fairly apply the rules to the facts and hold someone accountable if they violate the rules.
"That is what has been done here and that ultimately sends a very strong deterrent message to not only other coaches who might be tempted to cheat in the ways that were done here, but it also sends a signal to those who are doing it the right way - that the right way is the only way to compete in sport today.
"No longer can you abuse athletes and control athletes to harm themselves or attempt to break the rules in a fashion that is not permitted.
"That undermines the very value of what sport is supposed to be."