On Tuesday, Georges St-Pierre admitted one of the reasons he vacated his UFC welterweight title last month was due to the lack of drug testing support he received from the promotion leading up to his UFC 167 fight against Johny Hendricks.

"It bothered me enormously," St-Pierre said in French to a group of reporters in Montreal.

"That's one of the reasons why I stopped fighting. Not really to teach them a lesson, because that would also punish me. I wanted to do something for the sport. I love the sport. I see the direction it's going, and I don't think it makes any sense. This is stupid."

In a scrum video posted on RDS.ca, St-Pierre is seen answering questions about his decision to indefinitely leave the sport. However, when a reporter begins to ask about the drug testing issues he faced leading up to UFC 167, St-Pierre cracked a big smile, somewhat in relief, and said, "Oh, here's someone who reads between the lines. That's good." It appeared as though St-Pierre was just itching for someone to ask him about this subject, and once someone did, the flood gates opened for the usually guarded St-Pierre.

"I tried to do something to change the sport," he said. "Unfortunately, there were other people, for different reasons, maybe for money, in fear of losing money, because if you canceled the fight because someone tested positive there are millions of dollars [lost]. Also, the sport's image ... If you start testing everyone, how many will get caught? I don't want to say in public because I don't want to accuse anyone, but the sport's image will be hurt.

"Don't forget, I have internal information. I'm an athlete. I know what goes on, so that disappointed me greatly."

In September, UFC president Dana White said he thought both St-Pierre and Hendricks "looked stupid" for their public dispute over how they would be tested prior to their title fight. This came after St-Pierre offered to personally pay for Hendricks to be tested by the Voluntary Anti-Doping Association (VADA). Hendricks initially accepted the offer but then backed out, citing concerns with VADA's impartiality.

"I think it makes them both look stupid. These guys are going to get tested by the athletic commission," White said on a FOXSports Google Hangout.

"This is something that Georges St-Pierre wants to prove to everybody, because for years people have been saying (he's on PEDs). When he fought B.J. (Penn), B.J. talked smack about him. Other people have talked stuff. The kid, not only is he another guy that's been with us since day one, he's never tested positive for anything even remotely close to anything bad. He's never tested positive for anything. He's always been a straight shooter and always professional, yet people keep talking smack about him. I just think it's crazy for him to even do this."

In the end, after a public back-and-forth, only St-Pierre was randomly tested by VADA, and a month before UFC 167, St-Pierre told La Presse he was "very disappointed" by the UFC's lack of support in this matter. He hinted at these feelings on the conference call to announce his departure last month, but wasn't as clear about his feelings as he was on Tuesday. When White was asked on the conference call if he thought this issue led to St-Pierre's decision, he simply said, "no."

On Tuesday, St-Pierre stopped short at naming names. He didn't point a finger at White, Hendricks or anyone else, but he made it very clear that this was a major reason why he has no plans to fight any time soon.

"The only thing I want to say is, I wanted to do something to help those who are honest in the sport. Believe me or not, I never took drugs in my life. I'll take a lie detector test, I don't care. I'm for anti-doping tests. I think it's a big problem in the sport.

"This is a relatively new sport. There's one organization that has a monopoly, so the fighters don't have much power. They can't really talk because if one says what he thinks, he will get punished.

"If we want the sport to be accepted worldwide, like baseball, hockey, football, soccer, I believe [drug testing] is the thing to do. I think it's just a matter of time before it happens, it's just that I tried to make it happen now. Maybe they didn't like the idea because if I did it now, it would lead to others doing it and maybe that's not something they wanted to happen.

"It disappointed me. You know that there are things I can't say. I'm holding back. I'm a public person."

St-Pierre, who said he is still actively training and is in "excellent shape," announced on Tuesday that his GSP Foundation would give six athletes $15,000 a year for three years to train in six disciplines (karate, taekwondo, boxing, wrestling, fencing and judo). According to GSP's manager Rodolphe Beaulieu, the purpose is "to encourage school and athletic performance."

The 32-year-old St-Pierre said his family was very supportive of his decision to leave the sport last month, but once again, he left the door open for a return in the future. If certain things change, of course.

"No wants to talk about [drugs in MMA], but I think we need to talk about it. It's a problem.

"I wanted to remain diplomatic, but unfortunately there were people who weren't ready to change things. I'm certain it's a question of time. And maybe if things change one day, I'll return."