George H. Morris, the foremost trainer in equestrian competition and a former coach of the United States Olympic team, was barred for life from the United States Equestrian Federation on Monday as a result of an investigation into “sexual misconduct involving a minor,” according to the published details of the suspension.

The permanent suspension, which appeared online on Monday, is the most severe meted out by the United States Center for SafeSport, an independent investigative body charged with examining sexual misconduct in Olympic sports, according to Dan Hill, a spokesman. While SafeSport does not publicly announce its findings in order to protect victims, Mr. Hill said that the designation of a permanent suspension was “reserved for the most egregious cases.”

In a bulk email sent to people who follow his clinics and master classes, Mr. Morris, 81, said he would appeal the decision, which he said stemmed from allegations about actions that took place over four decades ago.