A third-party investigation found physical abuse persists in Japan's traditional sport of sumo, according to its final report.

The investigative panel, under the guidance of former prosecutor Keiichi Tadaki, questioned wrestlers and sumo elders and reported that over the past year, 5.2 percent of the Japan Sumo Association's membership said they suffered some form of physical violence outside the ring last year, according to the report published Friday.

This figure, although down from the 37 percent reported in 1979, comes with the awareness that violence between wrestlers often goes unreported to the heads of the sumo stables. The report concluded that the sumo world has not sufficiently learned from the 2007 death of an apprentice wrestler at the Tokitsukaze stable.

A year ago, an investigation into the assault by former yokozuna Harumafuji on fellow Mongolian wrestler Takanoiwa at a bar, revealed other senior wrestlers were present. Harumafuji, who chose to retire after the incident became public, reportedly struck the junior wrestler with a remote control for not paying attention to what the senior wrestlers were telling him.

The report concluded that yokozuna Hakuho's presence indicated some level of tolerance for using physical violence as a method of instruction. The report said that the number of violence-related scandals was high among foreign wrestlers, concluding that perhaps moral lessons were being neglected in favor of physical training for success in the ring.

The report suggested sumo elders who fail to eliminate physical violence in their stables have their credentials revoked or be punished in some other way.

"It is those in charge who must eradicate physical violence," Tadaki told a press conference.

The panel, formed in February, also asked association members who had quit over the past 10 years to cooperate with the investigation.