legal ground
Article 64 of the Civil Procedure Law of People's Republic of China (PRC)
The parties have the responsibility to provide evidence for their claims.
The people's court shall investigate and collect evidence that the parties and their agents ad litem cannot collect on their own due to objective reasons, or evidence that the people's court considers necessary for hearing a case.
The people's court shall comprehensively and objectively examine and verify the evidence in accordance with legal procedures.
Article 65
The parties concerned shall provide evidence of their claims in time.
The people's court shall, according to the litigant's claim and the trial of the case, determine the evidence that the litigant should provide and its time limit. If it is really difficult for the parties to provide evidence within the time limit, they may apply to the people's court for an extension of the time limit, and the people's court shall extend the time limit appropriately according to the application of the parties. If a party fails to provide evidence within the time limit, the people's court shall order it to explain the reasons; If the people's court refuses to explain the reasons or the reasons cannot be established, it may reject the evidence according to different circumstances, or accept the evidence but admonish it and impose a fine.