The president of messaging app provider Line Corp. said Tuesday that data from its users in Japan, now being stored in South Korea, will be transferred to databases in the country to better protect customers' personal information in the wake of exposure of such data to a Chinese affiliate without user consent.

Data management of Line, used by over 86 million of Japan's some 126 million people, is now under increasing scrutiny after the firm said last week that users' data stored in Japan had been accessed by technicians in China without informing them as required by law.

It has raised concerns over privacy and national security as data on personal, corporate and other users in Japan could have been transferred to the Chinese government.