The latest law on the subject appears to be :
1) Sanction under Sec 197 of Cr. P. C. is necessary mandatory where government servant could not have been removed from post with sanction of a authority prescribed under rules. Case: Fakhruzamma, Supreme Court, Date 12/12/2013
2) Sanction under Sec 19 of Prevention of Corruption Act is also mandatory, if such objection is taken at earliest point of time. After trial has progressed considerably, such technical objection is not considered strong enough by courts to drop proceedings.
