A former Samsung executive has been charged in South Korea with stealing trade secrets worth hundreds of millions of dollars.

According to prosecutors, the 65-year-old former Samsung worker is accused of stealing clean-room and factory blueprints from the company in 2018 and 2019.

In the Chinese city of Xian, where Samsung already has a chip factory, the suspect allegedly tried but failed to establish a copycat production facility, according to the Suwon district prosecutor’s office.

The unnamed man, who is being held in custody pending trial, stole data that South Korea regards as “national core technology” — a group of technologies that, if made available to the public abroad, could be hazardous to the nation’s economy and national security.

He was formally charged on Monday, according to the prosecution, after having been in custody for some time.

He was referred to as a “top expert in semiconductor manufacturing” and had been employed in the field for many years.

According to South Korean authorities, Samsung would have paid at least $236 million for the information that was allegedly stolen.

“It is a serious crime that can have a tremendous negative impact on our economic security by shaking the foundation of the domestic semiconductor industry at a time when competition for chip production is intensifying every day,” prosecutors said in a statement on Monday.

“The semiconductor industry accounted for 16.5% of South Korea’s total exports in 2022… and is a national security asset.”

Along with the executive, six others have been charged with theft-related offenses.

China informed operators of “critical information infrastructure” last month to stop purchasing Micron’s products after the American chip giant was found to have failed a national security review.