if police pressurized to withdraw the complaint

Yes i do endorse with expert Janakimanohar Rao sir advise.

Hello!  

Section 154 of Criminal Procedure Code, 1973 makes it obligatory for the police to file an F.I.R if the complainant approaches the police and the same should be done without any delay. It is the responsibility of the police to write down the complaint and get it signed by the complainant. Police under no circumstances can refuse to take down the FIR.  

Once the FIR is taken down, the police must further investigate the offence. Police cannot force a person to take back the complaint filed by him. If in case they are doing so, the complainant can approach the superintendent of the police by writing the complaint and sending it through the post. If this remedy does not work, he or she can directly approach the magistrate and file a complaint to him directly under Section 200 of the Criminal Procedure Code and the magistrate will direct the police to comply with the provisions of the Code.  

Once the FIR has recorded, it becomes part of the police records of that particular station and it does not matter if the police InCharge has been changed after filing the FIR. He cannot ask the complainant to register the complainant again because he is the new police InCharge. He can get a copy of the FIR in the police station itself.  

Best Regards,         

Vasundhara Singh 

If the police is putting pressure to withdraw the complaint, then the complainant can escalate the complaint to the higher police officer of the city/district  and seek its intervention  and proper legal action on the complaint pending before them.

If this step also fails to fetch any positive action from the police  then the complainant is at liberty to approach judicial magistrate court with a petition under section 156(3) cr.p.c. seeking direction to the concerned police to investigate and initiate proper legal action on the complaint. 

It could be that your father is called to the Station to record his statement and investigate the complaint. 

Police has asked you or your father for preliminary investigation ?

Whether any complaint has been accepted and acknowledged by police ? 

Whether FIR has been registered or not yet ? If no, FIR has so far been registered and the offence is cognizable, report it to higher police officers. Even then police did not register FIR consult and engage a local prudent lawyer to file a complaint before area Magistrate for issuance of direction to police.