The raids began on Wednesday morning and continued all night.
On Wednesday, searches were also conducted in Rao’s office in the state secretariat and in several other places connected to Rao, his son and others.
According to IT officials, raids were held in 12 locations.
A senior official in the IT Department said cash in new currency was seized from the raided premises.
Ironically, Rao holds the additional charge of Vigilance Commissioner and the Commissioner for Administrative Reforms.
Rao was appointed to the post overlooking the seniority of several IAS officials.
Informed sources said the searches of Rao’s residence and office were linked to the earlier IT raids on the residence of businessmen J. Shekhar Reddy, Srinivasalu and Prem.
The IT department recently seized 177 kg of gold and cash totalling Rs.96 crore in old 500 and 1,000 rupee notes and Rs.34 crore in new currency from the three.
A contractor, Reddy had reportedly executed a lot of work for the Tamil Nadu government. The Central Bureau of Investigation (CBI) arrested all three on Wednesday.
Leaders of the DMK and PMK demanded the immediate dismissal of Rao.