TOKYO • Japanese Olympic badminton medal hope Kento Momota made a sombre apology yesterday, after jeopardising his place at August's Rio de Janeiro Games by visiting an illegal casino.

The world No. 2, who last year became the first Japanese man to win a World Championship medal, and fellow offender Kenichi Tago face being booted off the Olympic team by the country's ruling body.

"I wanted to help bring joy and strength to the people of Fukushima by competing at the Rio Olympics," said the 21-year-old, who grew up in Fukushima, close to the site of the 2011 nuclear disaster.

"I deeply regret betraying everyone's support and expectations," added Momota at a press conference aired live on television.

"I had a duty to lead the Japan team but I let my curiosity get the better of me."

Japanese officials are set to hold an emergency board meeting this weekend to decide what action to take after the pair's team, NTT East Japan, confirmed they placed bets at an underground casino which was raided by police last year.

Nippon Badminton Association secretary general Kinji Zeniya had promised harsh sanctions on Thursday, insisting it was "probably impossible" for the players to represent Japan in Rio.

Momota, who has withdrawn from his defence of the Singapore Open title next week over the controversy, appeared to have dyed his highlighted hair black again as an act of contrition as he admitted to visiting the casino six times and gambling away 500,000 yen (S$6,200).

He has already secured qualification to the Olympics, and Tago, 26, begged officials to allow the star to compete in Rio.

Tears running down his face, Tago said: "I don't care what punishment I get, even if I can never play badminton again. My only wish is you give Momota another chance."

Tago had gone to several illegal casinos some 60 times over two years, spending roughly 10 million yen.

Gambling is largely illegal in Japan and people found guilty can face jail terms of up to five years.

AGENCE FRANCE-PRESSE, REUTERS