Rahul Mahajan, accused in a drug abuse case, and Sudhanshu Mittal, his late father Pramod Mahajan's aide were questioned by the Delhi police on Sunday.
This was Rahul's first interrogation after he was released on bail on June 14.
Both of them were interrogated at the Tughlaq Road police station by a team led by Assistant Commissioner of Police Suman Nalwa.
Rahul's questioning comes barely three days after he sought permission to leave for Mumbai as his late father's New Delhi residence had to be vacated by July 3.
Mittal was questioned as he had rushed Rahul to Apollo Hospital after a party in the wee hours of June 2. He had also handed over the two plastic packets, found at Rahul's residence, to doctors who, in turn, handed them over to police.
The medico-legal certificate prepared by the hospital names Mittal as the person who handed over the packets to doctors.
Police believes Mittal and another Mahajan aide Harish Sharma had ordered cleaning up of the room after Rahul was rushed to the hospital, which led to 'destruction of evidence'.
Complete coverage: The Rahul Mahajan case
