Swimming Australia (SA) has sacked coach Michael Palfrey after he triggered a media storm at the Paris Olympics by saying he hoped a South Korean athlete would beat Australian rivals at the Games.

Palfrey, one of the Australian swim team's Olympic coaches, told media days before the Games that he hoped world champion Kim Woo-min would win the men's 400 metres freestyle in which Australia's Sam Short and Elijah Winnington were also contenders.

Olympic swimming coaches are often freelancers who work with multiple nations' swimmers.

"I really hope (Kim) can win, but ultimately, I really hope he swims well," Palfrey told media at Paris, adding: "Go Korea."

Palfrey's comments triggered a fierce reaction from team officials and the Australian Olympic Committee, which said he had made a "serious error of judgement".

However, he was allowed to continue in his role at the Olympics.

SA said on Friday it had sacked Palfrey for breaching his contract "by bringing himself into disrepute and causing serious damage to his and Swimming Australia's reputation, and adversely affecting Swimming Australia's interests."

SA CEO Rob Woodhouse confirmed Palfrey's employment had ended with immediate effect, SA said in a statement.

Palfrey could not immediately be reached for comment.

Winnington and the Australian's team head coach Rohan Taylor told reporters in Paris that Palfrey had apologised to them for his comments.

Palfrey coached Zac Incerti, Abbey Connor and Alex Perkins on Australia's Olympic team, while also working with breaststroker Sam Williamson.

Germany's Lukas Maertens won the 400m freestyle, with Winnington claiming silver ahead of bronze-winner Kim.