“We are interrogating Amit Kumar and it is too early to describe his role in the racket. Our teams are on the lookout for the absconders in the case,” CBI spokesman G Mohanty said. “We are contemplating questioning the key accused (persons) in the custody of the Gurgaon and Moradabad police. Soon we will seek production warrants for them,” Mohanty added.

Following UP government’s announcement to hand over the probe to the CBI, Assistant Superintendent of Moradabad Police Manzil Saini reached the agency headquarters on Sunday to share the information about the case.

Earlier, Chief Metropolitan Magistrate Sanjiv Jain sent Amit Kumar alias Santosh Rameshwar Raut to CBI custody till February 22.

The CBI sought the custody of the 43-year-old doctor to conduct “thorough investigation” into the racket involving about 600 illegal kidney transplants.

In the hearing that lasted for about half an hour, the CBI contended that Kumar's interrogation would reveal the trail of millions of rupees involved in the decade-old racket.

Kumar would be produced before CBI's Special Court in Ambala in Punjab again on February 22.