Explanation:

Sections 41, 43 and 44 of Code of Criminal Procedure 
41. When police may arrest without warrant.—(1) Any police officer may without an order from a Magistrate and without a warrant, arrest any person
43. Arrest by private person and procedure on such arrest.—(1) Any private person may arrest or cause to be arrested any person who in his presence commits a non-bailable and cognizable offence, or any proclaimed offender, and, without unnecessary delay, shall make over or cause to be made over any person so arrested to a police officer, or, in the absence of a police officer, take such person or cause him to be taken in custody to the nearest police station. (2) If there is reason to believe that such person comes under the provisions of section 41, a police officer shall re-arrest him. (3) If there is reason to believe that he has committed a non-cognizable offence, and he refuses on the demand of a police officer to give his name and residence, or gives a name or residence which such officer has reason to believe to be false, he shall be dealt with under the provisions of section 42; but if there is no sufficient reason to believe that he has committed any offence, he shall be at once released. 
44. Arrest by Magistrate.—(1) When any offence is committed in the presence of a Magistrate, whether Executive or Judicial, within his local jurisdiction, he may himself arrest or order any person to arrest the offender, and may thereupon, subject to the provisions herein contained as to bail, commit the offender to custody. (2) Any Magistrate, whether Executive or Judicial, may at any time arrest or direct the arrest, in his presence, within his local jurisdiction, of any person for whose arrest he is competent at the time and in the circumstances to issue a warrant.