Besides the IT department, Vadra is being investigated by the Enforcement Department under the provisions of PMLA pertaining to allegations of money laundering in the purchase of a London-based property worth 1.9 million pound.
The ED said Thampi is also under the scanner for his reported dealings with some politicians and bureaucrats.
Agency sources had said the NRI businessman is also under the scanner for his reported dealings with some politicians and bureaucrats.
Thampi has been charged by the agency in the past in alleged illegal hawala dealings and land purchase case in the country in 2017.
Vadra is facing allegations of money laundering in the purchase of a London-based property -- at 12, Bryanston Square -- estimated at 1.9 million pounds (over Rs 17 crore).
The court, however, did not allow Robert Vadra, brother-in law of Congress President Rahul Gandhi, to go to London.
Vadra was issued fresh summons by the agency after claiming they had got new evidence in the money laundering case.
However, sources in the Congress said Priyanka Gandhi would not contest the 2019 Lok Sabha elections.
The court said Vadra will not leave the country without prior permission.
The ED had quizzed Vadra in Delhi for three days in connection with a money laundering probe against him for allegedly procuring assets abroad in an illegal manner.