China's Pan Zhanle has no questions to answer about his sensational 100 metres freestyle swimming world record at the Paris Olympics, British sprint specialist Ben Proud said on Thursday.

Pan smashed his own record with a time of 46.40 seconds in the last race of the night at the La Defense Arena on Wednesday. Australian silver medallist Kyle Chalmers was a massive 1.08 seconds behind.

"I think 46.4 changes swimming, for sure," Proud told reporters after winning his 50 metres heat.

"It's a huge drop, it's fantastic and it shouldn't be questioned.

"It was a great swim by a good athlete and all the other stuff should be taken care of behind the scenes by the people who are in charge. I mean, we sat and watched and just thought wow. I'm not going to swear but...

"It was just a phenomenal swim and to do that in the final against the best in the world, winning by a second, is something you won't see very often."

The Chinese swim team has been in the spotlight since revelations in April that 23 of its athletes competed at the 2021 Olympics despite testing positive for a banned heart medication.

The World Anti-Doping Agency accepted the findings of a Chinese investigation that the results were due to contamination from a hotel kitchen, and an independent review backed WADA's handling of the case.

The affair has hung over the Olympic meet and Pan complained after his gold medal on Wednesday that he had been given the cold shoulder by some rivals.

"We all do our thing, and for me I'm the only person I can trust flat out. Whatever happens behind the scenes, that's out of my control," said Proud, the 2022 world champion at 50 metres freestyle.

"I just love to watch people swim and swim well and, yeah, to be a part of it."