CBI officials from Delhi reached the residence of Rao around 9 am and continued the searches till 3.30 pm, sources said.
The officials of the central agency, who participated in the searches, however, refused to comment.
CBI also conducted searches at other locations, including office premises of Rao's company Saubhagya Media, besides the residence of Rao's daughter here, they said.
The investigating agency has accused Rao and his company of alleged criminal conspiracy, cheating and relevant sections of provisions of the Prevention of Corruption Act.
Rao, a former Congress Rajya Sabha MP and noted Telugu film producer/director, was Minister of State for Coal between 2004-06 and again between 2006-08.
He has already been quizzed by the agency in connection with the probe in coal block allocation scam.