Dr Amit Kumar, alleged kingpin in kidney transplant racket, was remanded in CBI custody till February 22. He was produced before Chief Metropolitan Magistrate Sanjeev Jain at his residence by the CBI in New Delhi on Sunday. Earlier, in a new twist to the case, CBI sources told NDTV that Dr Amit said he was running a clinic in Noida in a house rented out by a senior UP bureaucrat.