Regulations Governing the Customs Management of Freight forwarders Article 12

The forwarder shall pay attention to inspection; all illegal activities discovered, such as cargo smuggling or tax evasion, shall be immediately reported to the local Customs and the discovered objects and respective documents shall be turned over to the said authority.A forwarder shall provide full cooperation and assistance in smuggling investigation conducted by the Customs.
中文原文 海關管理承攬業辦法第12條
承攬業對於所承攬運送之貨物,發現有走私、漏稅或其他違法情事時,應即通知當地海關,並將該貨物及相關資料送繳海關。
承攬業遇有海關調查走私案件時,應切實配合協助辦理。

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