The Enforcement Directorate and Income Tax department on Tuesday raided firms linked to former Union Minister P Chidambaram's son Karti Chidambaram in Chennai.
The raids were conducted by the agencies on Vasan Eye Care and Advantage Strategic, a company that is also involved in the Aircel-Maxis deal.
Searches were conducted mainly in Chennai as part of a joint operation by the Enforcement Directorate and the Income Tax department.
In August, the Enforcement Directorate had summoned two directors from Karti Chidambaram's company in connection with Aircel Maxis scam.
ED was probing the financial transaction between Karti and Aircel just before the company was given approval from the Foreign Investment Promotion Board.