• Winner of 100m breaststroke has repeatedly criticised Russia’s Yulia Efimova
• KIng also hit out at her US team-mate sprinters Justin Gatlin and Tyson Gay

Lilly King is not sorry. She has called out her Russian rival Yulia Efimova for cheating three times this week. On Tuesday, after King won the 100m breaststroke final, she criticised her two team-mates on the track and field team, Justin Gatlin and Tyson Gay, too. King is unequivocal. “Do I think people who have been caught doping should be on the team? They shouldn’t,” she said. “It is just something that needs to be set in stone.”

King, 19, is as tough as they come. On Wednesday, after she had qualified for the semi-finals of the 200m breaststroke, she explained: “My parents raised me to say what I wanted to say even if it wasn’t what people wanted to hear necessarily. That’s always been how I am. I’ll stick to my guns.”

Efimova also made it through to the semi-finals of the 200m. Unlike King she did not stop to talk to the press. Since Tuesday Vladimir Salnikov, the head of the Russian Swimming Federation, has been doing her talking for her. “She has a long road to go in sport,” Salnikov said of King. “I hope, and I think in the end she will understand there are certain rules, there’s a procedure that regulates the participation of athletes. Of course she has the right to her opinion but you need to be objective and you need to be honourable.” King said she had not heard what he had said, and added: “I’m assuming it wasn’t that positive.”

“I obviously got some negative backlash, which I expected,” King said, “but for the most part the support has been very positive.” As she mentioned earlier in the week, she is simply saying what a lot of other people are thinking. Fina, the international swimming federation, should be embarrassed that a 19-year-old competing in her first Olympics has taken a lead on this issue while it has remained silent. It may cost her. She did not swim very well in the heats. She explained that the reaction to what she had said had been “a little bit overwhelming” and that she was “still trying to get off my phone and focus on my race”.

Efimova was also right to say that she has been singled out. There are four other Russians competing here who, like her, were cleared to compete only at the last minute. But they do not attract the same degree of attention. It is just that Efimova is the most successful of them. One of the others, Natalia Lovtcova, competed in the heats of the 100m freestyle but did not qualify. Lovtcova failed one test in 2008, and another in 2012, when she claimed she made the mistake of drinking from a team-mate’s contaminated water bottle. Unlike Efimova, who is based in the US, Lovtcova lives, trains and competes in Russia.

While the rivalry between Efimova and King is just beginning at these championships, another, far friendlier, is entering its final few races. Michael Phelps and Ryan Lochte, friends and wingmen, have been racing against each other for well over a decade now and have won 37 Olympic medals between them. The night after they combined to win the latest of them, in the 4x200m freestyle relay for the USA, they were both back in the pool to compete in the heats of the 200m individual medley. Lochte backed King – “I guess that’s her and that’s us. If we don’t like something, we’re going to say” – though did not add any observations of his own about Efimova.

Lochte has never really been noted for his eloquence, though he did once try to trademark his personal catchphrase “Jeah!” The sport will miss him, like Phelps, when he is gone.