Can police remand without fir

It is often the case when the police arrest a person in suspicion of a crime they are unable to complete the investigation in 24 hours. At this juncture when they require the accused or suspect to be kept away from society at large for the protection of society, of the accused or for the purpose of ensuring his availability for investigation, they may produce him before a magistrate, who may allow for the suspect to be held in the custody of the police or the judiciary.