In October, Yokozuna Grand Champion Harumafuji hit and injured a fellow Mongolian wrestler, Takanoiwa, during a night out drinking. Harumafuji retired from sumo the following month.

The board of directors of the association last week unanimously decided to recommend that Takanoiwa's stablemaster, Takanohana, be removed from his post as a director of the association.

The board cited Takanohana's repeated failure to cooperate with its internal investigation, despite reporting the assault to police.

An extraordinary meeting of the association's key decision-making body on Thursday unanimously agreed to remove Takanohana as director and demote him.

The chair of the council, former senior vice education minister Yasuko Ikenobo, told reporters that Takanohana had failed to report on the assault to the association and refused to cooperate with its internal investigation.

She said Takanohana's actions are unacceptable as a director of a public-interest corporation and that he neglected his duties.

It was the first time that a director of the association has been removed.

Ikenobo said Takanohana reportedly expressed his acceptance of the dismissal.