The former silver medal-winning swimmer became ill during training in Florida.
The Hong Kong-born born swimmer moved to Sydney when he was two and won silver as part of the 400 metre medley relay squad at the 2013 World Championships in Barcelona.
"(To) felt unwell at a training session and was taken to hospital where sadly, he passed away," A spokesperson for the Hong Kong Sports Institute said.
"Kenneth was known as a truly exceptional person, warm, funny and kind."
The cause of death was not immediately clear.