As their custody was ending Monday, the Anti-Corruption Bureau (ACB) of Telangana produced them before the magistrate, who extended their remand by two weeks.
The agency informed the court that the investigations in the case are continuing and the statement of nominated member Elvis Stephenson is also yet to be recorded in the case.
The Telugu Desam Party (TDP) legislator was arrested by the ACB on May 31 while he was offering Rs.50 lakh to Stephenson to make him vote for TDP-BJP candidate in legislative council elections.
The ACB, which had laid the trap on a complaint by Stephenson, also arrested Revanth Reddy's aides Sebastian Harry and Uday Simha.
The agency said the deal was struck for Rs.5 crore and Revanth Reddy had come to pay Rs.50 lakh as advance. The entire episode was recorded on a spy camera at Stephenson's house.
The ACB had questioned the three accused during the four-day custody.
The case took a dramatic twist on June 7 when an audio tape of Andhra Pradesh Chief Minister and TDP president N. Chandrababu Naidu's alleged telephonic conversation with Stephenson was aired on some television channels.
Telangana's ruling Telangana Rashtra Samithi alleged that Naidu is the mastermind in the case. The Andhra government, however, termed the audio tape "fake" and demanded probe into phone-tapping by the Telangana government.
Revanth Reddy, who was released on 12-hour bail on Thursday to enable him to attend his daughter's engagement, on Monday moved Supreme Court for bail.