A 63-year-old gangster has been arrested on suspicion of hiding around 9 kg of stimulants in his apartment, drug enforcement officials with the health ministry said Tuesday.

Shin Sanai, a resident of Yokohama and head of a gang associated with Inagawa-kai, a major crime syndicate, is suspected of violating the Stimulants Control Law, the Health, Labor and Welfare Ministry officials said.

the ministry said the drugs have an estimated street value of 540 million yen.

Inagawa-kai has been designated as a crime syndicate by prefectural public safety commissions charged with supervising local police forces.

In addition to the drugs, six guns and 95 bullets were seized, the officials said, adding they are investigating the alleged firearms violations in cooperation with Kanagawa Prefectural Police.

On Friday, Sanai was found with 14 plastic bags containing stimulants at his apartment, according to investigations.

Sanai is suspected of selling the stimulants to individual users by phone, the officials said.