PANAJI: The anti-corruption branch of the directorate of vigilance has registered a case against former Congress chief ministers Digambar Kamat and Pratapsingh Rane, former mines minister Somnath Zuwarkar, and politically influential mine owner Prafful Hede and six others in connection with illegal mining in Goa. The case pertains to alleged illegality in granting of no objection certificate for mining lease to Hede, apart from treating the offender as if the offence hadn't taken place.