The 45-year-old businessman, who is also the son of former Union minister P Chidambaram, was questioned for eight-and-a-half hours today in a corruption case. He has denied any wrongdoing and claimed the allegations against him are politically motivated.
The questioning took place days after the Supreme Court said Mr Chidambaram must join the investigation and undergo questioning.
He had been called by the agency twice earlier -- on May 18 and July 21. The first time, he had been abroad. On the second occasion, he had asked the agency for a reprieve, saying he had approached the Madras High Court challenging the case against him and the CBI should wait for the verdict.
The case dates back to 2007 and involves a private firm, INX Media. The company, which at the time was being run by Peter Mukerjea and his wife Indrani Mukerjea, had allegedly raised funds from abroad to the tune of Rs. 305 crore, although they had approval for only Rs 4.62 crore.
The investigators say Karti Chidambaram had made it possible for them to break the foreign investment regulations through "influence in the finance ministry" in exchange for kickbacks amounting to Rs 3.5 crore. His father P Chidambaram was the finance minister of the Congress-led UPA government at the time.
The former minister had denied the allegation. "I had never allowed any family member to speak to me or to any officer of my ministry on any official matter," he had said.
The Mukerjeas are currently in jail allegedly for the murder of Indrani Mukerjea's daughter Sheena Bora.