Additional Solicitor General (ASG) K.M. Natrajan submitted before the court that the documents and other materials collected during the probe showed that as a Finance Minister Chidambaram had granted approvals beyond his limit.
The court was hearing the case of alleged irregularities in grant of Foreign Investment Promotion Board (FIPB) approval in the Aircel-Maxis deal.
"The applicants committed serious economic offences, which are threat to the national economy and are white collar crimes. The offences have been committed systematically with cognisance out of larger conspiracy against the public and national interest," Natrajan said.
Such offences related to larger conspiracy in connection with transactions abroad, he said and added the investigation was still underway. The Letters Rogatory had been sent to different countries to seek information, he added.
"We have collected strong evidence and materials to make a case under the Prevention of Corruption Act and the Prevention of Money Laundering Act (PMLA)," Natraj told the court seeking custody for detailed investigation.
Opposing the prosecution's claims, defence counsels Abhishek Manu Singhvi and Kapil Sibal contended that attempts were being made to prejudice, humiliate and create camouflage to deny interim protection Chidambaram.
They said when the CBI had not called Karti Chidambaram for questioning since December 6, 2014, where did the question of something 'earth-shattering' arose. They argued that their clients would not fail the "triple test" of flight risk, non-cooperation and tampering with evidence.
The approval was allegedly granted in 2006 when Chidambaram was the Finance Minister. According to the foreign direct investment (FDI) rules, Chidambaram was only empowered to give approval to proposals involving up to Rs 600 crore foreign investment.
( With inputs from IANS )