DMK President M. K.Stalin said he had spoken to Raju over the phone and wished him a speedy recovery.
Raju is the third Tamil Nadu Minister to be infected by coronavirus.
He is also the 11th lawmaker in the state and seventh from the ruling AIADMK party to test positive for the coronavirus infection.
Earlier, six lawmakers, including Electricity Minister P. Thangamani and Higher Education Minister K. P. Anbalagan tested positive for the virus.
The other lawmakers affected by Covid-19 are K. Palani (Sriperumbudur), Amman K. Arjunan (Coimbatore South), N. Sathan Prabhakar (Paramakudi) and Kumaraguru (Ulundurpet).
Former Minister and Senior AIADMK leader B. Valarmathi also tested positive for the coronavirus infection on Monday and has been admitted to a private hospital here for treatment.
Four lawmakers of the DMK too have tested positive in the state. They are K. S.Masthan (Gingee), R. T.Arasu (Cheyyur), Vasantham K. Karthikeyan (Rishivandhiyam), and J. Anbazhagan (Tiruvallikeni-Chepauk).
Anbazhagan succumbed to the infection last month.