Sleuths raided proprieties, including CCD's office here. Searches are being conducted at over 20 locations across the country, including those in Bengaluru, Mumbai, Chennai and Chikkamagaluru, Income Tax department sources said.
Krishna had joined the BJP in March this year after he resigned from the Congress.
Siddhartha is the founder-owner of CCD, a chain of coffee outlets in India, and has been its chairman and managing director since January 17, 2015.
He is also an investor and has stakes in some IT firms, including Mindtree, and is among the largest exporters of coffee bean in the country.