The agency started a preliminary enquiry this week after material evidence indicated he had amassed property and valuables which did not match his income, CBI sources claimed.
The sources also said an explanation would be sought from Srivastava, who is now on bail in the alleged graft case registered by the CBI in January.
The CBI had also booked middleman Hemant Gandhi, Central Excise Superintendent Lallan Ojha and businessmen Dalip Aggarwal and Anand Aggarwal in connection with the case.
The agency had filed its charge sheet in the case on February 29, indicting Srivastava, Ojha and Gandhi, besides the Aggarwals.
The CBI had alleged Gandhi was in touch with Srivastava, Ojha and others and was acting as a middleman for them to obtain the bribe from the businessmen.
"It was alleged that a managed farce search of the importer's office was conducted by the Central Excise team headed by the aforesaid Superintendent on the instructions of the Commissioner. No records were created before, during or after the searches. Initially, an illegal gratification of Rs 2 crore was allegedly demanded, which was finally settled for Rs 60 lakh," a CBI spokesperson had alleged.
The spokesperson had said the middleman collected illegal gratification of Rs 20 lakh as well as a "self" cheque of Rs 20 lakh from the importer for not taking any action.