The Regulations Governing the Implementation of the Imposition of Countervailing and Anti-Dumping Duties Article 18

Where necessary for the investigation and determination of the case, the competent authorities shall extend the respective period as set forth in the Regulations up to one half of the respective period.The competent authority shall notify the extension of the aforesaid period to the applicant and any known interested parties in writing, and shall make a public notice thereof.
中文原文 平衡稅及反傾銷稅課徵實施辦法第18條
主管機關對於案件之調查、認定,必要時得就本辦法規定之各項期間延長二分之一。
前項期間之延長,應即以書面通知申請人及已知之利害關係人,並公告之。

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