“There was nothing that would have violated legal or regulatory limits,” said a spokesman for Line. “We will continue to respond to laws and regulations in all jurisdictions, including Japan.”
Government officials responsible for overseeing data protection were not immediately available to comment.
Four engineers from a company in China who perform system maintenance for Line were allowed to access servers in Japan from 2018, which contained the names, telephone numbers and email addresses of the users, local media said.
The reports come as Japan tightens the laws and regulations governing the use and storage of personal information by Internet companies.
Line with 186 million users worldwide – almost half of them in Japan – has since blocked access to User data At the Chinese subsidiary, the company spokesman said.
Line became part of Z Holdings, formerly Yahoo Japan, earlier this month, creating a $ 30 billion domestic Internet heavyweight to compete against local and US competitors.
Messages sent via Line can only be read by the sender and recipient, as the app, like other messaging apps, continuously encrypts the message content.
Z Holdings is controlled by SoftBank Corp through Holding A Holdings, which is jointly owned by SoftBank Corp and the South Korean Naver Corp, the former operator of Line.
Z Holdings, which plans to invest 500 billion yen ($ 4.58 billion) in technology over the next five years, announced the merger of the line last year but had to abandon the move due to the COVID-19 pandemic October move.
Line has expanded its business to include cashless payments and, more recently, telemedicine.
Shares in Z Holdings, which also control fashion retailer Zozo Inc and office supply company Askul Corp, fell 2% to 605.5 yen in morning trading, compared to the Tokyo Stock Exchange’s TOPIX index, which was unchanged.