Following Japanese media reports on Thursday, Toshiba has brought a civil suit against SK Hynix Inc. alleging that proprietary technical information related to NAND flash memory had been leaked to the Korean company. The case was brought at the Tokyo District Court, under Japan's Unfair Competition Prevention Act. Toshiba seeks damages for "the wrongful acquisition and use of Toshiba's proprietary technical information related to NAND flash memory," which Toshiba owned since 1987 and now jointly develops and produces with SanDisk.

Toshiba filed the suit on learning that a former employee of SK Hynix has been arrested in Japan for alleged criminal infringement of the Unfair Competition Prevention Act. The employee formerly worked for SanDisk in a NAND flash memory development project conducted in partnership with Toshiba at Yokkaichi Operations, Toshiba's flash memory technology development and mass production base in Mie prefecture, Japan. The employee is alleged to have illegally taken Toshiba's proprietary technical information in 2008, and to have subsequently provided it to SK Hynix.

Although SK Hynix is a business partner of Toshiba, the two companies remain competitors in NAND flash memory. Given the scope and importance of the misappropriated technical data involved, Toshiba said it had no reasonable option other than to seek legal redress.

Moving forward, Toshiba said it would construct a more robust system for protecting its intellectual property and preventing its loss.

For its part, SanDisk has also filed a civil lawsuit against SK Hynix, Inc., SK Hynix America and related entities in Santa Clara Superior Court. The lawsuit "seeks damages, an injunction and other remedies against Hynix for trade secret misappropriation" under California's Uniform Trade Secret Act.

Additionally, SanDisk has submitted a criminal complaint with the Tokyo Metropolitan Police Department against the former Toshiba former employee.

Hynix has not provided any comment yet.