Ryan Lochte said he felt "a little hurt" after two men rushed the stage following his performance on "Dancing with the Stars."
The two men, wearing anti-Lochte T-shirts, were arrested on suspicion of criminal trespassing, Los Angeles police spokesman Officer Mike Lopez said.
Sam Sotoodeh, 59, and Barzeen Soroudi, 25, both of Los Angeles, had rushed the stage while Lochte was getting his scores from judge Carrie Ann Inaba for his debut performance during Monday night's live installment of the celebrity ballroom dance competition, law enforcement sources told NBC News.
"Hey, back off," Inaba said as the altercation was occurring off screen.
Police called the incident a "pre-planned" action.
When the show returned, "Dancing with the Stars" host Tom Bergeron explained they were interrupted by "a little incident" and thanked the ABC series' security team "for staying in shape."
The two men were detained by security until police arrived to take them into custody, Los Angeles police spokesman Mike Lopez said.
At the same time, four or five women shouted "liar!" and were escorted out of the audience, the network said.
No one was injured or listed as a victim in the incident, Lopez said.
Olympic swimmer Ed Moses posted video of the incident on Instagram. It showed security guards holding down a man and escorting him out. Employees were also seen escorting out a group of women wearing anti-Lochte T-shirts.
"This crap is getting old!" Moses wrote. "I love u @ryanlochte and respect you putting yourself out there, you are one of a kind!! ... #respect"
Lochte told Bergeron that "so many feelings are going through my head right now." Lochte added that he was "a little hurt, but I came out here. I wanted to do something I'm completely not comfortable with, and I did."
Lochte later spoke with E! News about the event, saying "It's hard. I'm getting over it, though. It honestly feels as if someone reached inside, took out my heart out and just stepped on it."
ABC did not immediately return messages seeking comment about the incident. BBC Worldwide Productions, wich produces the show, said in a statement: "Two individuals stormed the dance floor tonight and were immediately subdued and escorted out of the building. The matter is now being handled by the authorities."
ABC News Radio reporter Jason Nathanson tweeted a photo showing two men who were wearing anti-Lochte T-shirts in handcuffs.
During the episode, the Olympic medalist performed a foxtrot routine with professional partner Cheryl Burke to "Call Me Irresponsible." They received a combined score from the judges of 24 out of 40.
"I'm hurt for Ryan," Burke said after the incident. "He's sweet, he's kind."
"He's working his butt off," she added. "I hope people give him a chance."
Lochte and teammates have seen scorn from some since they were involved in an early-morning drunken encounter during the Olympics last month at a gas station in Rio de Janeiro, Brazil. They later claimed they were threatened and robbed.
Lochte eventually said he "over-exaggerated" his description of what happened.
United States team officials banned Lochte for 10 months, requiring him to forfeit $100,000 in bonuses and miss the 2017 world championships.