Summer McIntosh became the first Canadian athlete to take three golds from a single Olympics when she won the 200 metres individual medley at the Paris Games on Saturday.

The 17-year-old swimmer did it in an Olympic record time of two minutes 06.56 seconds, taking down the 2016 record of 2:06.58 set by Hungary's Katinka Hosszu, to complete a medley double after winning the 400 last Monday.

Kate Douglass of the United States won the silver and Australian Kaylee McKeown was awarded the bronze after U.S. swimmer Alex Walsh, the 2021 silver medallist, was disqualified for an illegal turn at the end of the backstroke leg.

McIntosh now has four medals from Paris after also winning the 200 butterfly on Thursday and taking silver in the 400 freestyle on the opening Saturday.

"It's pretty surreal," she said. "I'm just so proud of myself for how I've been able to recover and manage these events, because it is a lot."

Walsh was visibly upset and did not stop to speak with reporters after leaving the pool deck but Douglass, the 200 breaststroke gold medallist last Thursday, said she was heartbroken for her.

"She deserved to win that medal and she deserved to be on the podium with me," she told reporters.

"When we swim that race together, it's fun to, you know, be on the podium together. So I was really upset for her.

"There's really nothing you can say in that moment to make it better. I tried my best but, you know, it's not my place to comfort her there."

Walsh's younger sister Gretchen, who won gold in the later mixed 4x100 medley, watched the race and then heard about the disqualification while in the cool-down pool.

"I was just stopped in the middle of the pool, so upset. I don't really know how to describe it," she said.

Douglass led after the butterfly leg but faded as McIntosh hit the front with the backstroke. Walsh then led at the 150 mark, but the Canadian powered back in the freestyle.

Silver was a step up from the bronze Douglass won at the Tokyo Olympics three years ago, while the bronze was backstroke queen McKeown's seventh Olympic medal and third from Paris.

McKeown's teammate Ella Ramsey, the eighth-fastest qualifier, did not start the final after the team reported she had tested positive for COVID.