Regulation on the Management of Classified Records Article 22-1

If the original government agency which approved the classification levels of the classified record is dissolved or merged with another authority or reorganized, the change or declassification of the classification levels shall be conducted by the take-over agency. If there is no take-over agency, the superior agency of the original government agency or the competent authority shall be responsible.
中文原文 機密檔案管理辦法第22-1條
機密檔案之機密等級原核定機關已裁併或職掌調整者,機密等級變更或解密,由承受其業務之機關辦理;無承受其業務機關者,由原核定機關之上級機關或主管機關為之。

English translation for reference only; the Chinese text prevails. Not legal advice.