Lilly King - the 19-year-old swimmer who took home gold after chastising a Russian rival - issued a strong statement about doping in the Olympics

U.S. swimmer Lilly King, whether the 19-year-old intended to or not, is spearheading the anti-doping contingency at the Olympics.

After taking gold over Russian swimmer Yulia Efimova - who had previously served a 16-month ban for testing positive for a steroid - in the 100-meter breaststroke Sunday, King threw shade at Efimova, saying, "It was so incredible, winning a gold medal and knowing I did it clean."

It was an extra jab at Efimova, who King took issue with Sunday after Efimova raised a finger to say "I'm No. 1" when she took first in her 100m breaststroke qualifying heat. King later mocked Efimova when she won her heat, and chastised Efimova's history of doping.

In a somewhat awkward press conference after winning gold on Monday, with Efimova sitting by her, King said she stood by her statements about Efimova and doping. When a reporter asked King if she thinks US sprinter Justin Gatlin should be on the team after twice failing drug tests and being suspended, King again stood her ground.

"Again, I have to respect [the IOC's] decision, even if it's not something I necessarily agree with. No, do I think people who have been caught for doping offenses should be on the team? No, they shouldn't.

"It's unfortunate that we have to see that, and then it's such a toss-up in between sports and in between countries. It's just something that needs to be, you know, set in stone that this is what we're gonna do to settle this and that should be the end of it. There should not be any bouncing back and forth."

King later answered a question about Australian Mack Horton, who called his win over China's Sun Yang a "win for clean athletes." King supported Horton's comments.

"Total props to him for speaking out first, I admire that. But he said what everyone was thinking, and I also said what everyone was thinking. So, I do think it is a victory for clean sport and just to show you can do it while competing clean for your whole life."

As Sports Illsutrated's Tim Layden noted, Gatlin's suspension was served six years ago. The validity of calling him out can be questioned.

But regardless, King is right about the need for policy reform, and to have a young, unwavering swimmer speak out against it is turning into a great Olympic moment.