Official sources said the raids are being conducted in Delhi and Chennai since early morning.

The central probe agency, on December 1 last year, had conducted similar searches on the premises of a relative of Karti and others in this case.

The ED case pertains to the Foreign Investment Promotion Board (FIPB) approval granted in 2006 by the then finance minister P Chidambaram.

The agency had said it is investigating “the circumstances of the said FIPB approval granted by the then finance minister (P Chidambaram)".

The ED also alleged that Karti has "disposed" of a property in Gurgaon, which he had allegedly rented out to a multinational company "to whom foreign direct investment (FDI) approval had been granted in 2013".

It charged that Karti had "also closed certain bank accounts and attempted to close other bank accounts in order to frustrate the process of attachment" under the PMLA.

The agency said FIPB approval in the Aircel-Maxis FDI case was granted in March, 2006 by the then FM even though he was competent to accord approval on project proposals only up to Rs 600 crore and beyond that it required the approval of the Cabinet Committee on Economic Affairs (CCEA).

"In the instant case, the approval for FDI of 800 million USD (over Rs 3,500 crore) was sought. Hence, CCEA was competent to grant approval.

"However, approval was not obtained from CCEA," it alleged.