An agriculturalist by occupation, Krishnan became involved in social work as the secretary of the Red Cross Society in his native village.
He took a keen interest in serving the poor and otherwise disadvantaged and was arrested on several occasions in connection with various agitations in favour of the people of Tamil Nadu.
[3] Krishnan was Minister of State Highways and Ports in the Government of Tamil Nadu from 1998 to 2001.
Several arrests were made and when the DMK came to power in Tamil Nadu in 2006, the case was transferred to Chittoor in Andhra Pradesh after the All India Anna Dravida Munnetra Kazhagam (AIADMK) sought intervention by the Supreme Court of India.
The AIADMK said that a fair trial might not be possible in a Tamil Nadu court because the primary accused, M. K. Alagiri, was the son of Karunanidhi, by then the DMK Chief Minister.