Toshiba and SanDisk are seeking damages from SK Hynix in separately filed lawsuits, both of which allege the company profited from the theft of data surrounding NAND flash memory technology.
Toshiba and SanDisk have partnered for years to produce the flash memory chip technology used in mobile devices including smartphones and tablets. Toshiba is currently the second-largest manufacturer of NAND memory chips in the world by revenue and market share.
On Thursday, Tokyo police arrested a former SanDisk engineer under the suspicion of providing NAND flash memory technical data to Hynix in 2008. The engineer once worked at a joint venture manufacturing plant with Toshiba, leaving SanDisk to work for Hynix.
Toshiba has filed a suit against Hynix within the Tokyo District Court, whereas SanDisk has filed a separate claim in Santa Clara Superior Court, California. SanDisk has also filed a criminal complaint against the engineer.
Toshiba has not revealed what compensation or damages it is seeking -- although estimates damage caused by the alleged data leak resulted in losses of $980 million -- but SanDisk said it is seeking compensation, an injunction and "other remedies," according to Reuters.
South Korean firm Hynix said it has not yet received the litigation.
In 2004, Toshiba sued Hynix for the alleged infringement of memory patents, and after three years, the dispute was settled with cross-patent licensing. The two companies are also both currency working on next-generation memory technology.
In a statement, Toshiba said:
"Moving forward, Toshiba will construct a more robust system for protecting its intellectual property and preventing its loss."