Customs Anti-smuggling Act Article 9

For the necessity of suppressing smuggling, Customs may inspect the import goods, export goods, through goods, transit goods, bonded goods, parcels, baggage, transportation means, warehouses or other places of storage, and the persons concerned at the scene.
中文原文 海關緝私條例第9條
海關因緝私必要,得對於進出口貨物、通運貨物、轉運貨物、保稅貨物、郵包、行李、運輸工具、存放貨物之倉庫與場所及在場之關係人,實施檢查。

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