Procedure to be adopted when the Police Dep. is to be legally sued?

When one fels that the POLICE is a party to the conspiracy in implicating one in a false ault criminal case, can the Department be sued for this dirty game played ? and is there any procedure to be followed to file legal complaint in the Court of Law and is the Police Department equally responsible for causing unnecessary harment and the accused having gone through the trauma till thecase was decided and eventually the accused being acquitted. Now to cause further harment, the Police and the Complainant have joined hands to go into an APPEAL against the trial court judgement, the accused having been acquitted