According to the Customs Law of the People's Republic of China:
Article 37 The goods under the supervision of the Customs shall not be opened, withdrawn, delivered, exchanged, modified, mortgaged, pledged, retained, transferred, changed in mark, transferred to another for use or otherwise disposed of without the approval of the Customs.
Customs Gazette seal, no one may open or damage.
Customs seal is not allowed to open, is to bear legal responsibility.