According to The Star, Kuala Lumpur police chief Amar Singh confirmed the case but declined to provide further details as investigations are ongoing.
The suspect, who is said to be in his 30s, was arrested after the victim lodged a police report on Sunday.
The New Straits Times, quoting sources, said the man was from China, while the victim was a backup diver for the Malaysian team in the recent SEA Games.
The suspect is believed to have been with the national team since 2012.