TOKYO (Kyodo) -- Grand champion sumo wrestler Harumafuji, who has nine career titles, is suspected of assaulting and injuring fellow wrestler Takanoiwa late last month in a drunken brawl, sumo sources said Tuesday.
Harumafuji, who submitted paperwork to pull out of the ongoing Kyushu Grand Sumo Tournament the same day, did not deny the initial media report as he bowed to reporters and expressed remorse after morning training.
"Regarding Takanoiwa's injury, I sincerely apologize for causing trouble to his stablemaster, his stable, the Japan Sumo Association and my stablemaster," Harumafuji said.
"I cannot comment further until my stablemaster comes back."
The JSA announced Monday that eighth-ranked maegashira Takanoiwa has been diagnosed with concussion, skull base fracture and cerebrospinal fluid leak among other injuries, and revealed that he been hospitalized from Nov. 5 to 9.
Takanoiwa was one of the early withdrawals from the Nov. 12-26 tournament. He is expected to miss the entire meet and be demoted to the lower juryo rank at the meet in January.
Both wrestlers at sumo's top makuuchi division are from Mongolia. Harumafuji, 33, fights out of Isegahama stable, and the 27-year-old Takanoiwa belongs to the Takanohana stable.
Harumafuji was drinking with other Mongolian wrestlers on Oct. 26 after a regional tour in Tottori, when the yokozuna, angered by Takanoiwa's attitude, struck him with a beer bottle, according to a Sponichi report.
On Tuesday morning, JSA executives including chairman Hakkaku gathered at the tournament venue in Fukuoka Kokusai Center, where they questioned Harumafuji, his stablemaster Isegahama and Takanoiwa's stablemaster Takanohana.
Since his professional debut in 2001 under the ring name Ama, Harumafuji has won the championship nine times, his last title coming at the autumn meet in September when he competed as the only yokozuna while the other three pulled out due to injury.
In September 2012, he earned promotion to yokozuna, becoming the third consecutive Mongolian-born wrestler after Asashoryu and Hakuho to achieve the top rank.
Despite his bid for a second title this year, Harumafuji lost his first two bouts in Fukuoka and will forfeit his scheduled third-day bout against top-ranked maegashira Tamawashi. He is withdrawing from a meet for the eighth time in his career.
Yokozuna Kakuryu withdrew earlier due to injury, leaving only two grand champions -- Kisenosato and Hakuho -- with 13 days remaining in the sellout tournament.
"He put on a strong performance to prove his worth as yokozuna in the last basho so it's disappointing that he has to pull out this way. It throws a wet blanket on an exciting tournament," said former NHK announcer Kunihiro Sugiyama.
The incident sent shock waves across the country, reminding fans that the ancient sport has yet to recover from a reputation tainted by scandals over match-fixing, violence and bullying.
In 2010, Mongolian yokozuna Asashoryu retired from the sport followed allegations that he attacked a man outside a Tokyo nightclub in the middle of the New Year tournament.
In June 2007, the police arrested stablemaster Tokitsukaze and three wrestlers who beat 17-year-old Tokitaizan to death using a beer bottle, a wooden stick and a metal bat. The junior wrestler, whose real name was Takashi Saito, died from shock from multiple trauma.