Legal analysis: The Criminal Procedure Law has no restrictions on the time for questioning witnesses, only the time for summoning and subpoenaing criminal suspects. The maximum time for summoning or detaining a criminal suspect shall not exceed 12 hours.
Legal basis: Article 117 of the Criminal Procedure Law of the People's Republic of China
For criminal suspects who do not need to be arrested or detained, they may be summoned to the city where the criminal suspect is located. The interrogation shall be conducted at a designated place in the county, county or place of residence, but the certification documents from the People’s Procuratorate or the public security organ shall be presented. Criminal suspects found at the scene may be summoned orally upon presentation of their work IDs, but this shall be noted in the interrogation transcript.
The time for summons or custodial summons shall not exceed twelve hours; if the case is particularly serious and complex and requires detention or arrest measures, the time for summons or custodial summons shall not exceed 24 hours.
Continuous summons or custodial summons shall not be used against criminal suspects. When summoning or arresting a criminal suspect, the criminal suspect shall be guaranteed food and necessary rest time.