legal ground
Article 39 of the Criminal Procedure Law of People's Republic of China (PRC)
Defense lawyers can meet and correspond with criminal suspects and defendants in custody. Other defenders, with the permission of the people's courts and people's procuratorates, may also meet and correspond with criminal suspects and defendants in custody. If a defense lawyer holds a lawyer's practice certificate, a law firm's certificate, a power of attorney or a letter of legal aid to ask for a meeting with the criminal suspect or defendant in custody, the detention center shall arrange the meeting in time, which shall not exceed 48 hours at the latest. In criminal cases endangering national security and terrorist activities, defense lawyers should obtain permission from the investigation organ when meeting with the criminal suspect in custody during the investigation.