What are the steps to take if a police officer (Investigating Officer) is acting corruptly, misusing their authority, and conducting a shoddy investigation?

If you believe a police officer is acting corruptly, you can file a complaint with their superiors, the Superintendent of Police or the Director General of Police. You can also lodge a complaint with the State Human Rights Commission or the National Human Rights Commission. Further, you can consider filing a Public Interest Litigation (PIL) in the High Court.