A source said Sebi planned to tag brokers based on their performance on areas such as compliance, investor protection and arbitration.

However, Deloitte, the latter entity, says regulations don't mandate it to go beyond a basic examination of the books of accounts.

The exchange has written to MCX for greater details on the special audit. BSE has sought the names of related parties, which have been withheld by MCX.

On May 16, the leads will start trickling in from morning but the final result is likely to come only after 3.30 pm, beyond trading time for the equities segment in India.