Preventive arrest requires strict statutory conditions; mere apprehension of breach of peace cannot justify detention.
Preventive arrest under Section 151 CrPC is lawful only where the police know of a design to commit a cognizable offence and believe arrest is necessary to prevent it; a mere apprehension of breach of peace or public nuisance is insufficient. On the facts, the material supported only proceedings for possible disturbance under preventive provisions, so the arrest and detention were unlawful. The Police Act did not supply an independent arrest power, and Section 79 IPC gave no protection because no good-faith mistake of fact or lawful justification was established.
Issues: (i) Whether the arrest and detention of the complainant under Section 151 of the Code of Criminal Procedure, 1898 were lawful when the material disclosed only apprehension of breach of peace and no cognizable offence; (ii) whether the respondents could justify the arrest under the Police Act or claim protection under Section 79 of the Indian Penal Code, 1860.
Issue (i): Whether the arrest and detention of the complainant under Section 151 of the Code of Criminal Procedure, 1898 were lawful when the material disclosed only apprehension of breach of peace and no cognizable offence.
Analysis: Section 151 empowers arrest without warrant only when the police officer knows of a design to commit a cognizable offence and believes that such offence cannot otherwise be prevented. The material before the Court showed, at the highest, a situation of possible breach of peace and disturbance of public tranquillity, which was pursued only through proceedings under Sections 107/117 of the Code of Criminal Procedure, 1898. A mere apprehension of disturbance or public nuisance is not equivalent to a design to commit a cognizable offence, and no lawful basis for arrest under Section 151 was established.
Conclusion: The arrest and detention were unlawful and were not justified under Section 151 of the Code of Criminal Procedure, 1898.
Issue (ii): Whether the respondents could justify the arrest under the Police Act or claim protection under Section 79 of the Indian Penal Code, 1860.
Analysis: The duty to prevent offences under the Police Act does not enlarge the power of arrest beyond the authority conferred by law. The provisions governing preventive arrest and the Police Act must be read harmoniously, and the latter does not create an independent power to arrest in the absence of legal authority. Section 79 also did not apply, because no mistake of fact or good-faith belief in lawful justification was made out; the only plea was that the arrest was lawful, which failed once the arrest was found unauthorized.
Conclusion: The respondents could not derive lawful authority from the Police Act, and Section 79 of the Indian Penal Code, 1860 afforded them no protection.
Final Conclusion: The acquittal was set aside and the complainant succeeded in establishing unlawful arrest and detention, leading to conviction of the respondents.
Ratio Decidendi: A police officer may make a preventive arrest only when the statutory conditions for arrest under Section 151 of the Code of Criminal Procedure, 1898 are strictly satisfied, and neither the Police Act nor a bare claim of subjective satisfaction authorises arrest in the absence of a cognizable offence and lawful justification.