legal ground
Criminal Procedure Law of the People's Republic of China
Article 170 The People's Procuratorate shall, in accordance with the relevant provisions of this Law and the Supervision Law, examine the cases transferred for prosecution by the supervisory organs. If the people's procuratorate considers it necessary to make supplementary verification after examination, it shall return it to the supervisory organ for supplementary investigation, and may make supplementary investigation on its own if necessary.
The people's procuratorate shall first detain the criminal suspect in the case that the supervisory organ has transferred for prosecution, and the lien measures shall be automatically lifted. The people's procuratorate shall, within ten days after detention, make a decision on whether to arrest, get a bail pending trial or monitor residence. Under special circumstances, the decision time can be extended by one to four days. The period when the people's procuratorate decides to take compulsory measures shall not be counted in the period of examination and prosecution.