What is basic difference between the statement recorded by a Police Officer U/S 154 and U/S 161 Cr.P.C.What is the purpose of two statement?

 INTRODUCTION:

        When F.I.R is launched regarding an offence, the police officer has to conduct an investigation regarding the offence committed to ascertain evidences regarding the commission of the offence.In this context, investigation officer records the statements of the persons whom he thinks are acquainted with the  case & such statements cannot be used for any purpose during the trial except for contradicting the statement of the same witness in the court.

2.RELEVANT PROVISIONS:

        Section 154, 161, 161A & 162 Cr,P.C