Theft of goods, breaking in to property, criminal trespassing and forcefully illegal possession of property are cognizable offences depend upon the fact and circumstance of each case. secondly vigilance report is good peach of evidence i advice you to file civil suit for permanent injunction if property belong to private person and file criminal complaint if construction took place on government land. beside if police is not taking any steps advice you to forward your complaint to higher official ( DCP, COMM. OF POLICE) for taking appropriate action in the matter. thereafter you can complain to judicial magistrate under section 156(3) on basis of criminal complaint.