Thampi, who was arrested by the agency on Friday in connection with the money laundring case involving bizman Robert Vadra, was sent to three-day ED custody after he was produced before Special CBI Judge Arvind Kumar on Saturday evening.
The agency said the arrest of Thampi comes in the wake of the investigation involving Vadra, who is being probed in a money laundering case involving foreign assets worth pound 1.9 million in the UK.
An ED official revealed that the agency has detected some alleged undisclosed transactions being made from other foreign countries for the purchase of these properties by people linked to Vadra.
The ED had found the link in the form of Thampi, through whom the financial probe agency suspects kickbacks were routed in a petroleum deal in 2009.
Thampi was questioned by the agency in April last year.
According to the agency officials, the discrepancies in Vadra's and NRI businessman's statements were the reason for Thampi's arrest. The ED official said that Vadra during his questioning on February 6 last year told the ED that he met Thampi on board an Emirates' flight.
Thampi in his statement to the ED stated that he met Vadra through Madhavan, personal assistant of Sonia Gandhi.
The official also pointed out another contradiction in Vadra's statement. He was asked whether he had any knowledge about 12 Bryanston Square (BSQ) property in London. "Vadra during questioning on February 7 replied that he has never stayed there. While Thampi in his statement on April 6 said that Vadra did stay at 12 BSQ in London," the official said.
Earlier, the ED, besides the "property number 12", Ellerton House, Bryanston Square, London, also identified five other properties. Those include 26 Wellington Road St John's Wood London, 25 Saratoga Road Clapton London, 42 Upper Brook Street London, Property on Edgware Road London and Flat Number 6, Grosvenor Hill Road, Bourdon Street, London.
Last year, the ED asked its UK counterpart to share details of ownership and financial transactions related to over half-a-dozen properties in the UK.
( With inputs from IANS )