The president of Japan’s Nippon Telegraph and Telephone West will step down at the end of March after the theft of data by a temporary worker dispatched to the company, The Japan Times reported. The data was leaked to a third party and the company has been given administrative guidance by the communications ministry for insufficient supervision.

“Our social responsibility is extremely grave. I'm stepping down to take the blame,” the newspaper quoted NTT West President Masaaki Moribayashi as saying.

The theft is believed to have occurred across a decade – long before Moribayashi became President. However, the company had been tipped off to a potential leak in 2022 by a client. Internal investigations not only failed to find the leak, but also gave misleading information about security measures, such as encryption software that was never used.

In a report, NTT West said it is working to strengthen its security to prevent similar incidents in the future. However, it noted that workers at the company were not aware that the information was being leaked illegally and there was no intention to hide that fact.

The former temporary employee was arrested in January and later indicted on 21 February 2024. The temp worked for NTT Marketing Act ProCX from 2008 to July 2023, engaged in the operation, maintenance and management of a server in which customer information was stored. Data was stolen by connecting a USB device to a computer and subsequently provided to a list broker.