The income tax (I-T) department initiated search operations on Friday at the residence of Tamil Nadu Health Minister C Vijayabaskar's residence and other locations.
The action comes at a time when his party is facing a by-election in R K Nagar, the Assembly seat which fell vacant after the demise of former chief minister J Jayalalithaa, on April 12.
According to reports, premises belonging to the minister in Pudukkottai and Trichy are also being searched. Around 100 officials are conducting searches in around 30 locations.
The tax sleuths had earlier searched the residence of P Rama Mohana Rao, when he was the chief secretary of the state. In a rare instance, the officials also searched his office at the secretariat during the time.
I-T officials have been conducting raids in various parts of the country to book tax evaders in the recent past.
The raid also comes at a time when the All India Anna Dravida Munnetra Kazhagam (AIADMK) government is facing a by-election amid a split in the party. Two AIADMK factions, one led by party secretary V K Sasikala and her relatives and the other lead by former chief minister O Panneerselvam, are contesting the election, apart from the Opposition Dravida Munnetra Kazhagam and a party formed by Deepa Jayakumar, niece of late J Jayalalithaa.