"I have all the evidence and when the time comes, (I will) prove the charges in court," Karunanidhi told the media.
The former chief minister spoke after Jayalalithaa threatened to sue him for making what she was said was a "wild reckless charge".
She said there was no need for her to write to MGR, as the AIADMK founder was known, when she used to meet him almost daily when he was the chief minister and she a key party functionary.
The war of words followed the Tamil Nadu government's decision to ban for 15 days Kamal Haasan's movie "Vishwaroopam" following protests by Muslim groups.
The Hindi version of the Tamil-Telugu film is set for release Friday.