The Central Bureau of Investigation (CBI) on Tuesday raided the house of former finance minister P Chidambaram and his son Karti in Chennai.
The raids were linked to clearances given to INX media, which was once owned by Peter Mukerjea, media reports said.
A total of at least 14 locations in Chidambaram's home city of Chennai were searched by the CBI, India's main federal crime-fighting agency, reports said.
Karti Chidambaram is facing money laundering probe in connection with the Aircel-Maxis deal of the 2G scam.
Shortly after media reports of CBI raids at Chidambaram's house in Chennai came out, the Congress came out to defend the former finance minister.
"What have you been doing for three years? If there were serious charges, go ahead. If you have evidence, establish it. You are destroying reputations. The people of India are watching this. You are still trying to fish and find out," Congress spokesperson Tom Vadakkan said.