|Asashoryu allegedly broke the nose of a Tokyo nightclub worker [AFP]
The high-profile sumo grand champion Asashoryu faces a potentially career-threatening probe into allegations of a drunken scuffle in Tokyo last month.
Newly elected Japan Sumo Association (JSA) executive board member Takanohana ordered an investigation following reports Asashoryu had allegedly broken a man's nose.
"It is important we get to the truth," former 'yokozuna' grand champion Takanohana said.
"The JSA needs to know exactly what happened.
"We need to launch a proper investigation.
"A sumo wrestler should not feel the wind at his back but walk tall and with his head held high."
The head of Asashoryu's sumo gym told Japanese media at the weekend the Mongolian had been too drunk to remember the alleged incident outside a nightclub in the early hours of January 16.
The 29-year-old won his 25th Emperor's Cup a week later but sumo officials have taken a dim view of his latest alleged breach of discipline.
Senior JSA figures have said Asashoryu will face punishment if the allegations were proven and Japanese media have speculated that he could even face the sack.
Asashoryu has frequently been in hot water during an explosive career, for everything from pulling an opponent's hair to starting a soapy bathroom brawl during a post-bout soak.
In 2007, Asashoryu was banned after being caught playing soccer in Mongolia, having forged a doctor's note for an apparent back injury.
His suspension triggered a bout of clinical depression, leading Asashoryu to seek solace at a luxury spa resort in his native country.
The JSA has set up a committee to look into the incident and plan to reach a decision by Thursday.