Regulations Governing Interview Implementation by the National Immigration Agency, Ministry of the Interior Article 14

If the NIA considers the applicant’s interview statements to be flawed, and require further verification, the NIA shall notify the interviewee to undergo an interview again.After nationals without household registration in the Taiwan Area, people of the Mainland Area, and residents of Hong Kong or Macau are interviewed in accordance with Article 4, if the NIA considers their case to be complex and is unable to render an immediate judgment, the NIA may allow the person to be inspected and then enter the Taiwan Area; the NIA shall then notify the person to go to an NIA-designated place to undergo an interview again within one month.
中文原文 內政部入出國及移民署實施面談辦法第14條
移民署對申請人接受面談之說詞認有瑕疵,有再查證之必要者,應通知二度面談。
臺灣地區無戶籍國民、大陸地區人民、香港或澳門居民依第四條規定接受面談後,移民署認案件複雜,無法為即時之認定者,得同意其經查驗後先行入境,並以書面通知其於一個月內,至指定處所接受二度面談。

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