Relevant laws and regulations:
Article 91 of the Criminal Procedure Law When arresting a person, the public security organ must produce an arrest warrant.
After the arrest, the arrested person shall be immediately sent to the detention center for custody. Unless it is impossible to notify, the family of the arrested person shall be notified within 24 hours after the arrest.
Article 92 People's courts and people's procuratorates must interrogate people who decide to arrest themselves, and public security organs must interrogate people who are arrested with the approval of people's procuratorates within 24 hours after arrest. When it is found that the arrest should not be made, it must be released immediately and a release certificate issued.