Explanation:

Section 125 of Evidence Act – 
[125. Information as to commission of offences. –– No Magistrate or police-officer shall be compelled to say whence he got any information as to the commission of any offence, and no revenueofficer shall be compelled to say whence he got any information as to the commission of any offence against the public revenue. Explanation.–– “Revenue-officer” in this section means any officer employed in or about the business of any branch of the public revenue.