Provided that, no sale shall be set aside on the ground of irregularity, unless the applicant satisfies the Collector that he has sustained substantial injury by reason of such irregularity.

Purchaser may apply to set aside sale under certain circumstances Purchaser may apply to set aside sale under certain circumstances.— The purchaser may apply to the Collector to set aside the sale on the ground that the defaulter had no saleable interest in the property sold; and the Collector shall, after due inquiry, pass such orders on such application as he deems fit.