Japan Sumo Association Chairman Musashigawa said Monday the governing body has to penalize Asashoryu if recent media reports about his drunken rampage were true.
"We need to know what really happened," Musashigawa said. "If Asashoryu did attack the man, we have to impose a strict punishment on him."
The Mongolian-born yokozuna was reported by weekly magazine Friday last week to have been "wrecked" before slugging an acquaintance, who was originally believed to have been his manager, outside a nightclub in downtown Nishiazabu in the early hours of Jan. 16.
Another tabloid-style magazine, Shukan Shincho, then reported that the man attacked in the incident and left with injuries that included a broken nose, was actually in charge of a dance club where the yokozuna had been drinking.
Asashoryu's stablemaster Takasago said last weekend that the yokozuna and the man have reached an amicable settlement and he was ready to submit written statements of verification to the JSA board.
Takasago, however, did not show up at Monday's board meeting.
"You contradict yourself if you lie to cover up a lie. We just can't trust Takasago on this issue," said Jun Yoshino, an outside member of the board and a former police executive.
Earlier in the day, a closely watched JSA board election, the first of its kind in eight years, saw reform-minded former grand champion Takanohana join the 10-man decision-making body.
The new board immediately held a meeting and decided to set up a committee to tackle the Asashoryu issue.
Meanwhile, the sumo association has postponed its plans to discuss a possible punishment for Asashoryu on Thursday.
Tomozuna, the head of the JSA investigative committee, said the committee needs more time to find out the truth and will provide only an interim report on that day, with a final report expected around Feb. 10.