(AFP) - Olympic medal hope Kento Momota has been kicked off Japan's badminton team for the Olympics this summer for gambling at an illegal casino, officials said on Sunday (April 10).

The Nippon Badminton Association threw the book at the 21-year-old world No. 2, banning him from competition indefinitely, after an emergency meeting to decide on the player's fate.

Team-mate Kenichi Tago, also found guilty of placing illegal bets, was removed from the organisation's official player list for an indefinite period.

Momota became the first Japanese man to win a world championship medal with a bronze in Jakarta last August and had been tipped to challenge for the title in Rio.

The controversy caused a stir last week, with Japanese badminton chief Kinji Zeniya breaking down in tears on television before resolving to deal harshly with the offenders. Government ministers were also quick to condemn the players.

Gambling is largely illegal in Japan. The incident comes after a betting scandal that sent shockwaves through the country's most popular sport, baseball, just as it is bidding for inclusion in the 2020 Tokyo Olympics.

Momota dyed his highlighted hair black as an act of contrition as he appeared in front of the cameras to apologise for his actions. He admitted visiting a casino six times and gambling away 500,000 yen (S$6,200).

His absence in Rio will be a major blow to Japan's medal hopes. He backed up his strong showing at the world championships by becoming the first Japanese player to win the Super Series Masters Finals in Dubai last December.

People found guilty of gambling in Japan can face jail terms of up to five years.

Publicly-operated gambling for sports such as horse racing and "keirin" bicycle racing is not illegal.