Japan Police Raid Yakuza Offices as Part of Sumo Gambling Scandal

(AFP) - Japanese police on Monday raided the offices of yakuza gangs in connection with a widening gambling scandal tarnishing the tradition-steeped sport of sumo.

The raids followed the arrests of three gangsters and a former sumo wrestler on Sunday on suspicion they extorted Y6 million ($A76,623) from a broker of illegal baseball gambling.

Sumo's governing body has said at least 27 wrestlers, masters and others from 13 sumo training centres or "stables" have admitted to illegally gambling on the results of Japanese professional baseball games.

Betting in Japan is permitted only on horse racing and certain motor sports.

Japanese media on Monday reported that officers from the Tokyo Metropolitan Police Department's organised crime division had entered the head offices of the yakuza groups in western Japan to which the gangsters belonged.

The gangs, based in Osaka, Nara and Fukuoka, are affiliated with the Yamaguchi-gumi, Japan's largest organised crime syndicate, with an estimated 36,400 members.

Japanese police prosecute individual yakuza for crimes, but the groups themselves are not illegal and operate out of corporate-style headquarters.

Tokyo police did not give details of the raids but confirmed the arrests.

The former wrestler arrested on Sunday, 38-year-old Mitsutomo Furuichi, and the gangsters had extorted the Y6 million payment from the unnamed gambling broker, who was himself a former wrestler, a police spokesman said.

Furuichi was angry because the broker had spread a rumour that Furuichi had financial trouble because of baseball betting - a story Furuichi believed had ruined the career of his own younger brother, an active sumo wrestler.

"You have shamed my younger brother... You must pay for this," Furuichi was quoted as telling the broker early this year as he enlisted the gangsters and threatened to kill the broker, a Tokyo police press officer said.

The gambling scandal has again shone a spotlight on sumo's murky ties to Japan's underworld, following recent revelations that top Yamaguchi-gumi members were given ringside seats at sumo tournaments.

Amid a public outcry, broadcaster NHK last month cancelled broadcasts of the Grand Sumo Tournament for the first time in over half-a-century.

Nevertheless, the yakuza-linked scandal seems unstoppable, with more stablemasters alleged to have signed business contracts with gangsters in order to finance the renting or buying of their stables.

The sumo association has set up a special panel to investigate ways of cutting the sport's links to gangsters, who are often "patrons" for sumo wrestlers, by studying similar efforts by Japan's professional baseball body.

The image of sumo has been tarnished in recent years by revelations of drug use, claims of match-fixing and the 2007 death of a trainee who had been the victim of a brutal "hazing" by his stable mates.