SEC Deputy Secretary-General Vasant Thienphom has clarified on the SEC's website that directors of public companies are required to vacate their directorship once the SEC files a criminal complaint. This suggests that the requirement to vacate arises early in the criminal proceedings upon filing of the complaint, which precedes any final judgment on the complaint by the applicable Thai court.
In addition, the Ministry of Commerce's Department of Business Development has issued a notification directing public companies that they must register a change in directors within 14 days of the criminal complaint being filed by the SEC.