(Bloomberg) -- Mizuho Financial Group Inc. said a former worker stole tens of millions of yen worth of clients’ property stored in safe deposit boxes, adding to concerns about the security of the service at Japanese banks.

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An employee who has since left Japan’s third-biggest bank took the assets from two customers in 2019, a company spokesman confirmed on Tuesday following local media reports. Mizuho reported the matter to the Financial Services Agency, the spokesman added.

The revelations come after a similar incident at Mitsubishi UFJ Financial Group Inc., which fired an employee who allegedly stole an estimated ¥1.4 billion ($9 million) from the safe deposit boxes of dozens of customers. Senior MUFG executives including banking unit chief Junichi Hanzawa took pay cuts over the matter.

Finance Minister Katsunobu Kato said the FSA will continue to look at the state of the deposit box business in the country, including any links to money laundering. Financial institutions need to adhere to proper responses regarding the boxes, Kato said at a regular news briefing on Tuesday after TV Tokyo reported the Mizuho incident.

MUFG is considering whether to keep the safe deposit box business and will make a decision by March, Hanzawa said last month. Some global banks including JPMorgan Chase & Co. have begun to phase out the service as they close branches to reduce costs and focus on digital offerings.

The incidents in Japan may shake the foundation of the banking business, which is built on the trust of customers. The country’s securities sector has also been tarnished in recent months by allegations that a Nomura Holdings Inc. employee tried to rob and murder an elderly couple at their home.

--With assistance from Erica Yokoyama and Takashi Umekawa.

(Updates with company confirmation and comments from Finance Minister)

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