Even if an fir has been registered and even if the police has made the investigation, or is actually making the investigation, which the aggrieved person feels is not proper, such a person can approach the Magistrate u/s 156(3) Cr.P.C., and if the Magistrate is satisfied he can order a proper investigation and take other suitable steps and pass such order orders as he thinks necessary for ensuring a proper investigation. All these powers a Magistrate enjoys u/s 156(3) Cr.P.C.
Dilawar Singh Vs. State of Delhi,[1]
[1] Dilawar Singh Vs. State of Delhi, AIR 2007 SC 3234 : (2007) CriLJ 4709 : (2007) 10 JT 585 : (2007) 10 SCALE 556 : (2007) 9 SCR 695 : (2007) 2 UJ 1108 : (2007) AIRSCW 5899 : (2007) 6 Supreme 153