The former minister was arrested last evening from his residence by a team including an ADSP and DSP, they said.
A case under section 120 B of the IPC (Criminal conspiracy) was registered against him.
'Kaamu' Suresh, DMK town secretary of Arumuganeri, a panchayat town in the district, was stabbed on March 1 by two persons while he was about to leave after participating in then Deputy Chief Minister M K Stalin's birthday function in Arumuganeri, police said.
After Radhakrishnan's arrest, he was taken to two police stations where he was interrogated in connection with the case, before being produced before a local court which remanded him to judicial custody, they said.
(Published 11 August 2011, 09:51 IST)