Kanagawa Prefectural Police arrested on Tuesday a former deputy manager at Hana Credit Union’s Yokohama branch on suspicion of stealing ¥619 million ($4.1 million) in cash from the branch's safe deposit boxes between September 2021 and March 2023.

Police are investigating the total damage, which could exceed ¥1 billion.

The 49-year-old suspect from Chofu, Tokyo, who was dismissed in February 2024, admitted to the allegations, telling police he used the stolen money to pay off debts and gamble, with police believing he gambled on horse and boat racing, according to the Asahi Shimbun.

Investigators believe the thefts began in 2016, when the man was assigned to the branch, and that he repeatedly accessed the safe deposit box room.

He is suspected of duplicating spare keys during the branch's 2017 relocation and engaging in more than 100 thefts outside business hours, according to NHK.

The credit union said it discovered missing key usage records during an internal investigation in October 2023 and consulted with police.

Hana Credit Union then disclosed the case in February 2024, fired the suspect and abolished safe deposit box services across all branches the following month.

“We take this misconduct seriously and will further strengthen our compliance framework, enhance employee education and work diligently to prevent any recurrent incidents," the credit union said in a statement at the time. "We will also reinforce our internal management system and make every effort as a united organization to restore trust.”

The case is the latest in a string of thefts involving bank employees and safe deposit boxes. Mitsubishi UFJ Financial Group in November revealed that a former employee had stolen gold bars worth tens of millions of yen from customers' boxes, while Mizuho Financial Group said in February that a former employee stole ¥66 million from safe deposit boxes at a Tokyo branch, raising questions about the security of financial institutions' safe deposit box services.

Translated by The Japan Times