Shigeharu Shirai, 72, a leading figure of one of Japan’s notorious “Yakuza” mafia gangs was wanted by the Japanese authorities for his alleged role in the murder of a gangland rival in 2003.
He is accused of shooting dead the boss of a rival faction, which resulted in the imprisonment of seven members of his gang for between 12 and 17 years.
He had fled to Thailand, married a local woman and melted into a seemingly obscure retirement before someone unwittingly posted photos of him playing a streetside checkers game with his distinctive gangland tattoos on display.
A missing little finger, which reflects a tradition by yakuza members of slicing off a fingertip in atonement for an offence, also provided a clue to his true identity.
The seemingly innocent images were shared more than 10,000 times and were spotted by the Japanese police, who alerted the authorities in Thailand.
Shirai was arrested during a shopping trip on Wednesday, in the central market town of Lopburi, north of Bangkok.
“The suspect admitted he was the leader of the yakuza sub-gang Kodokai,” said Thai police spokesman, General Wirachai Songmetta, referring to an affiliate of Japan’s largest yakuza gang, Yamaguchi-gumi.
“The suspect has not confessed to murder but has admitted that the victim used to bully him,” he added.
The mafia-like Yakuza gangs first operated in the 17th century, stemming from street merchants and gamblers. They are a transnational group of crime synidcates believed to have 60,000 members across 21 different factions.
During the chaos of post-war Japan, their underworld empire grew to become worth billions of dollars.
The gangs themselves are not illegal and even have dedicated offices and business cards.
However, much of their earnings come from illicit activities including gambling, prostitution, loan sharking, protection rackets, drug trafficking, cyber hacking and white collar crime.
Shirai had tried to keep a low profile during his stay in Thailand, the police said. He had received money to live on from a visiting Japanese man who came two or three times a year.
He was arrested for entering Thailand illegally without a passport or visa and will now be arrested to face prosecution in his homeland.