Four officials from Shanghai Customs have been put under investigation for corruption.

Shanghai Customs said on its website on Tuesday that the customs' discipline inspection department had already carried out an investigation into Bian Zuyao, the former deputy head of Shanghai Customs. The preliminary investigation result has been sent to the procuratorate. Bian and the three other officials have been under investigation by the procuratorate.

Shanghai Customs could not be reached by China Daily for comment.