(CNN) -- Japan's national sport of sumo wrestling was rocked by a match-fixing scandal on Thursday after it was revealed three wrestlers had admitted to rigging bouts.
"Three sumo wrestlers have admitted to match-fixing," Yoshiaki Takaki, the country's minister for education and sport, announced to a parliamentary panel.
''Sumo is our national sport. If match-fixing has occurred, it is a very serious betrayal of the people,'' Naoto Kan, the country's Prime Minister, added.
Japan's Kyodo news service claimed that Tokyo Police had found suspicious messages on a number of wrestlers' phones that suggested the outcome of several fights had been planned.
The messages exchanged between wrestlers discuss how fights would be arranged and also the amount of money that would change hands.
"I'll hit my opponent head on," was one message reported in British newspaper The Guardian.
"For 20 more I will concede. After the meet, I need to make at least 50 or I'll be in serious trouble," read a further text which discussed the financial rewards for one wrestler.
"You fall when I move to tackle," read another message reported by Japanese news wire Jiji Press.
Japan Sumo Association chairman Hanaregoma told a news conference that 13 people who had been mentioned in the messages would be investigated.
"It's a betrayal of sumo fans. If this is true. It would be something that rocks (sumo) to its foundations. We will investigate thoroughly," Hanaregoma said.
It is the latest controversy to hit sumo after a gambling scandal emerged in July last year when 34-year-old wrestler Ozeki Kotomitsuki is said to have illegally bet on baseball games.
