Grand champion Harumafuji admitted to assaulting lower-ranked competitor Takanoiwa during an alcohol-fueled brawl when questioned on the matter by a Japan Sumo Association crisis management panel Sunday, a senior association official said.

Kagamiyama, head of the JSA's crisis management department, said the case needs further examination as some details remain unclear, including whether, as reported, the 33-year-old Mongolian yokozuna struck Takanoiwa in the head with a beer bottle during the late-October incident.

After the two-hour interrogation at Tokyo's Ryogoku Kokugikan hall, panel chief Toshio Takano declined to disclose what Harumafuji said, while pledging to "report as soon as possible" on the case.

The JSA had said earlier the panel will fully examine the case and hand down a judgment or punishment sometime after the ongoing Kyushu Grand Sumo Tournament which ends on Nov. 26.

"He spoke in a matter-of-fact tone in line with what had happened. We listened to him faithfully," Takano, a former prosecutor, told reporters.

It was the first time the yokozuna had spoken to the JSA crisis management panel since the sport's governing body learned of the incident earlier this month.

The team is tasked with looking into specific details of the incident, including the alleged use of a beer bottle as a weapon.

Harumafuji was questioned by police on Friday and admitted that he injured fellow Mongolian wrestler Takanoiwa at a restaurant-bar in the western Japan city of Tottori, investigative sources said.

However, the yokozuna denied allegations that he struck No. 8 ranked maegashira Takanoiwa in the head with a beer bottle, saying he hit him with his bare hands, according to the sources.

The yokozuna was reported to have hit Takanoiwa with a beer bottle after he was angered by the 27-year-old looking at his smartphone while being scolded for his behavior.

Takanoiwa missed the ongoing Kyushu tournament after being diagnosed with head injury including a suspected fracture at the base of his skull and a cerebrospinal fluid liquid leak.

Harumafuji also withdrew from the tournament citing injuries, while apologizing for causing trouble due to the scandal.