Khanna is understood to have accorded sanction on Wednesday for prosecuting Kumar for spreading enmity between two communities.
The CBI had asked for prosecution sanction for four cases of rioting in Sultanpuri and Mongolpuri on November1, 1984.
The CBI had registered the case against Kumar after the G.T. Nanavati Commission report of February 2005, which called for fresh examination of complaints where he had been named but no chargesheet was filed.
Congress spokesman Shakeel Ahmed said, “Law will take its own course. Congress does not interfere in legal matters.”