Grand champion sumo wrestler Harumafuji was involved in a drunken brawl late last month that left fellow Mongolian competitor Takanoiwa hospitalized with serious injuries, his stablemaster admitted to sumo administrators on Tuesday.
Stablemaster Isegahama's comments were the first public acknowledgment of the incident.
According to a report in the tabloid Sponichi, 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.