Conte claimed that rival coach Trevor Graham had revealed the drug to US testers, acting "purely out of competitive jealousy" as Chambers was challenging Graham's trainees; Montgomery and Greene. Chambers denied that he had any knowledge that the substance he was taking was banned and claimed he was deceived by Conte over its true use. However, he contradicted his statement in a later interview, saying that he had major suspicions that he was using banned substances but was too naïve and lacking in self-respect to act otherwise. By Chambers' own admission in 2008, in a letter by his supplier Conte to British anti-doping chief John Scott, THG was not the only substance he had used during his career. In his confession he admitted to the use of epitestosterone cream, EPO, HGH, insulin lispro, modafinil and liothyronine.