On Sunday night, Efimova, who was booed during her preliminary race and semifinal, held up the "No. 1" sign after coming in first during the semifinal.
King had previously indicated that Efimova, who she beat in Monday's event, was a cheater.
After the final King was asked whether Gatlin, who will run in the 100m in Rio, and has previously been banned for drugs, should be on the U.S. team: "Do I think someone who has been caught for doping should be on the team?"
"You know, we have some tough young kids in our team and I think that's something special", Phelps said.
"I was always a backstroker growing up, so that was the event I always got super excited to watch for the Olympics". Gay was suspended for a year beginning in 2013 after testing positive for a banned substance. King said during an interview with reporters, referring to Efimova. King slammed Efimova on Sunday for being caught "drug cheating" and stated that she was "not a fan" of the Russian swimmer, reports Sputnik. "You can just try and understand me, like if you switch you and I".
"You're shaking your finger 'No".
I met the brash 19-year-old at the 2016 U.S. Olympic Swimming Trials in late June.
"I basically said what everybody's thinking", she added. King said she never considered congratulating Efimova.
Russian Federation argues it is taking steps to clean up sport and is being singled out for political reasons. Efimova pleaded her own case, ignoring Stepanova.
After the race, Efimova broke down, sobbing uncontrollably as she started to speak to journalists.
"I swam against dopers", Looze said.
Little more than an hour later Hosszu was back in action in the 200m individual medley semi-finals, where she's seeking to complete the medley double after winning the 400m IM in a world record on Saturday. But especially standing for what I believe is right, I felt that I needed to perform better tonight than I had in the past.
But King's criticism wasn't just reserved for her worldwide opponents. She also levelled her sights at her fellow Team USA athletes, such as Justin Gatlin, who had been caught doping in the past.
[On being asked if USA dopers should be allowed in the team] No. Michael Phelps backed King's stance, saying "It's kind of sad that today in sports in general, not just in swimming, there are people who are testing positive and are allowed back in the sport, and multiple times". It's something that needs to be set in stone that this is what we're gonna do to settle this and that should be the end of it. "There should be no bouncing back and forth".
Australian freestyler Mack Horton also was mad and he decided he was not going to take it anymore.
"It's so hard", she said, "knowing all the work you put in every day, and then to get here and be so far behind where you feel like you can be".
"If I had been in Yulia's position, I would not have wanted to be congratulated by someone who was not speaking highly of me". "To have somebody test positive not just once but twice and still have the opportunity to swim at these Games, it breaks my heart".