New Delhi: Former Finance Minister P. Chidambaram’s son Karti on Wednesday refused to appear before the CBI in an alleged graft case, seeking withdrawal of the summons issued to him till the Supreme Court decides his petition challenging the probe agency’s notice.

The CBI is investigating how Karti allegedly managed to get a clearance from the Foreign Investment Promotion Board (FIPB) in the Aircel-Maxis deal when his father was the Finance Minister in 2006.

His lawyer N.R.R. Arun Natarajan has written to the Central Bureau of Investigation (CBI) asking for the withdrawal of the summons asking him to appear before the agency for questioning.

The 45-year-old businessman was asked to appear before the CBI on Wednesday.

Seeking a probe into the role of Chidambaram, Swamy referred to the Comptroller and Auditor General’s 2015 report that pointed to two alleged illegalities.

According to Swamy, the CAG cited the illegality of FIPB approving Maxis’ acquisition of 93.3 percent stake in Aircel Tele Ventures Ltd through its wholly-owned subsidiary, the GCSHL, well in excess of the then ceiling of 74 percent investment by a foreign entity.

The second illegality, Swamy said, was that since the foreign investment in Aircel was more than Rs 600 crore, it should have gone to the Cabinet Committee for Economic Affairs for approval but was cleared by the FIPB.

Karti has been accused of receiving kickbacks from the Maxis Group in guise of software consultancy by a company he promotes.

“I request you to kindly withdraw the notice dated September 26 issued to my client…and wait for the orders of the Supreme Court,” Natarajan said in the letter.

“I request you to not insist on my client’s appearance before you on October 4 (Wednesday),” the lawyer wrote to the CBI.

Earlier also the CBI in its summons had asked Karti to appear at its headquarters on September 14 but he refused to do so.

In the letter, Natarajan said the trial court’s February 2 order discharged all the accused in the Aircel-Maxis case.

“The issuance of the present notice when all the accused have been discharged and the proceedings have been terminated is clearly illegal, mala fide and to harass my client and his family,” the advocate argued in the letter.

The CBI has alleged that the Malaysia-based Global Communication Services Holdings Ltd (GCSHL), a subsidiary of Maxis, had sought approval for an investment of $800 million in Indian telecom major Aircel.

Though it was the Cabinet Committee on Economic Affairs, headed by then Prime Minister Manmohan Singh, which was competent to grant the approval, the clear was given by the then Finance Minister Chidambaram, according to the CBI.

Bharatiya Janata Party MP Subramanian Swamy has alleged that Chidambaram had tweaked FIPB norms for clearing the Aircel-Maxis deal in 2006.