A bench of justices Altamas Kabir and J Chelameshwar issued notice on Rishi's petition which also sought direction to the CBI to permit an advocate to be present with him during questioning by the agency.
Appearing for Rishi, senior counsel Mukul Rohtagi told the bench that he was suffering from "cirrhosis of the liver with portal hypertension" and other complications, which required expert medical treatment.
He submitted that since Rishi was a British national and earlier undergoing treatment there, it was necessary for him to continue the treatment in England for at least 30 days.
The counsel submitted that Rishi was cooperating with the investigating agency and had visited them at least on 10 occasions, without giving scope for any complaint.
The Vectra group is being investigated by CBI in connection with alleged irregularities in the supply of Tatra all-terrain trucks to the public sector BEML.
The 57-year-old British national who has been named as an accused in CBI's FIR in alleged irregularities in purchase of the Tatra trucks, has been quizzed several times at the CBI headquarters here has a substantial stake in Tatra Sipox UK.
The CBI has registered a case naming Rishi and unnamed officials of Defence Ministry, Army and BEML on March 30 for alleged criminal conspiracy, cheating and relevant sections of the Prevention of Corruption Act.
The CBI is probing alleged irregularities in assigning of supply from then Czechoslovakia-based Tatra, with which the agreement was originally signed in 1986, to the Tatra-Sipox UK owned by Rishi in 1997 showing it as original equipment manufacturer and the fully-owned subsidiary of Czech company.