The CBI on Tuesday got three more days to interrogate former finance minister P Chidambaram's son Karti in the INX Media case.

The court extended Karti's custody after the probe agency argued that witnesses are being "approached" and evidence "tampered with".

Special CBI judge Sunil Rana's order came after vociferous arguments from Additional Solicitor General (ASG) Tushar Mehta, who appeared for CBI, and Karti's counsel Abhishek Singhvi, for about an hour. The court also posted the consideration of his bail plea to March 9. While the CBI demanded nine days custody, saying it "virtually" had only four days of questioning despite Karti being in custody for six days, the court gave only three more days.

Arguments and counter-arguments flew inside the courtroom with Singhvi accusing the CBI of having a "thirst for blood" for Karti's custody and interrogation till it gets an answer to its liking.

Mehta, while disagreeing with the charges, claimed that the scope of the case has now grown from "India to global, from rupees to dollars," without elaborating.

Mehta began his arguments by handing over a two-page note on developments that happened on Monday, which he did not want to say in an open court as it would affect investigations. He said the name of a "new company" has also come to light the day before (on Sunday).

Mehta, whose absence at noon when the remand application was called prompted an adjournment of the case till 2 pm, said Karti was not cooperating.

"We have made substantial progress... we have new material...(but) to every question, he is saying I am politically victimised...We have seized his phone but when asked, he said I will not give the password," Mehta said.

He also said Karti was taken to Mumbai where he was confronted with former INX Media promoter Indrani Mukerjea in Byculla prison.

Mehta said the CBI has video-recorded the Indrani-Karti face-to-face encounter.

Urging the judge to look into the higher courts judgements, Singhvi said, "The custody is to extract confession...unless you are a terrorist with a bomb who cannot be questioned without being kept in custody, one should go by settled legal provisions."

Singhvi added Karti is ready to appear before the investigators every day at a time stipulated by the courts.