The company said in a statement on Wednesday that Park had stepped down over his role in the breach. It appointed Harold Rogers, chief administrative officer for the retailer’s U.S.-based parent company Coupang Inc., as interim head.

Park becomes the highest-profile casualty of a crisis that’s prompted a government investigation and disrupted the lives of millions across Korea. Nearly two-thirds of people in the country were affected by the breach, which granted unauthorized access to their shipping addresses and phone numbers.

Police raided Coupang’s headquarters this week in search of evidence that could help them determine how the breach took place as well as the identity of the hacker, Yonhap News reported, citing officials.

Officials have said the breach was carried out over five months in which the company’s cybersecurity systems were bypassed. Last week President Lee Jae Myung said it was “truly astonishing” that Coupang had failed to detect unauthorized access of its systems for such a long time.

Park squared off with lawmakers this month during an hours-long grilling. Responding to questions about media reports that claimed the attack had been carried out by a former employee who had since returned to China, he said a Chinese national who left the company and had been a “developer working on the authentication system” was involved.

The company faces a potential fine of up to 1 trillion won ($681 million) over the incident, lawmakers said.

Coupang founder Bom Kim has been summoned to appear before a parliamentary hearing on Dec. 17, with lawmakers warning of consequences if the billionaire fails to show.

Park’s departure adds fresh uncertainty to Coupang’s leadership less than seven months after the company revamped its internal structure to make him sole CEO of its Korean operations. In his new role, Rogers will focus on addressing customer concerns and stabilizing the company, Coupang said.