Special CBI judge Arvind Kumar extended Thampi's custody till January 24.
During the course of the hearing, Enforcement Directorate counsel Amit Mahajan said, "We were not able to complete the probe in three days. There are a lot of documents which are very essential. In coming days we want to summon more people which we don't want to disclose."
"I won't blame the accused but the nature of investigation is such that it is taking time," he added.
Opposing the remand, Thampi's counsel Raju Ramachandran said, "16 appearances, 80 hours and with last three days 20 more hours have been added. 30,000 pages worth of documents have been seized. I am willing to appear before them twice a day unlike other accused who sought anticipatory bail even after having medical problems.
"His medical condition which is that he is suffering from prostrate cancer," Thampi's legal team said.
Thampi was arrested by the agency on Friday in connection with the money laundring case involving Vadra.
Thampi's role surfaced as it was noticed that arms dealer Sanjay Bhandari along with co-conspirators Robert Vadra and Thampi had evolved a scheme of money laundering by way of transferring the proceeds of crime multiple times from one individual to other to make investigation of the trail of proceeds of crime arduous and difficult.
( With inputs from IANS )