They said a total of 18 locations in Chennai, Namakkal and Tirunelveli are being raided since early morning hours.
In the first instance, tax sleuths are searching the premises of a contractor firm--PSK Engineering Construction Company-- on charges of routing and possession of alleged "unaccounted cash".
Three premises in Chennai and four linked to the company in Namakkal are being raided, they said.
In the second case, the Chennai investigation wing of the department is searching a group of cash handlers and financiers against whom the sleuths obtained information that they are allegedly "mobilising cash for possible use in elections."
The locations linked to two individuals identified as Akash Baskaran and Sujai Reddy are also being searched, they said.
While 10 premises in Chennai are being searched, one in Tirunelveli is being raided in connection with second case, they said.
Polls in the 39 seats of Tamil Nadu and the lone seat in Puducherry would be held on April 18, the second phase of the Lok Sabha elections.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)