A recent split in Japan's biggest yakuza crime syndicate may have put its top leader at serious risk of tax evasion charges like those that toppled Chicago mobster Al Capone, experts said Tuesday.
Police have warned of a possible gang bloodbath after a breakaway group broke off from the Yamaguchi-gumi earlier this year.
And the rival faction may have got its hands on sensitive information about illicit funds passed to gang leader Kenichi Shinoda, who is also known as Shinobu Tsukasa, experts said.
"Those that split off are believed to have data about how much Tsukasa has pocketed" over the years, freelance journalist and yakuza expert Atsushi Mizoguchi told the Foreign Correspondents' Club of Japan.
The rival gang could try to use that information to bring down their former boss by supplying it to police, he added.
"As far as there are memos showing when and how much cash was passed to him, the tax evasion charge would stand," Mizoguchi said.
Authorities have been cracking down on the long-tolerated yakuza, whose heavily tattooed members are infamous for lopping off their own fingers for even minor transgressions.
Like the Italian Mafia and Chinese triads, the yakuza engage in everything from gambling, drugs and prostitution to loan sharking, protection rackets and white-collar crime.
Observers said the biggest yakuza shakeup in years highlights problems in Japan's rigidly hierarchical organised crime groups.
A feeble economy and steadily falling membership hurt the bottom line, while less organised rivals muscled in on yakuza territory.
Before the Yamaguchi-gumi's high-profile split, losing more than 10 percent of its soldiers, the group led by Tsukasa boasted more than 23,000 members and was Japan's biggest single gangster group.
But the breakaway mobsters became angry at the millions of dollars which they had to hand over to top brass annually including Tsukasa, who is known for donning expensive Italian suits, Mizoguchi said.
The head of a rival yakuza group was recently arrested on tax evasion charges based on memos showing cash transfers, he added.
"Taxation is a very effective way to control the mafia, and it's used worldwide," lawyer Hideaki Kubori, an expert on Japan's anti-gang law, told the correspondents' club.
"Al Capone also went down due to tax evasion."