"I have enough evidence. I am ready to produce them in the court when Chief Minister files a complaint", Mr Karunanidhi said in a statement, after Jayalalithaa said she would initiate legal proceedings against him.
Mr Karunanidhi had on Wednesday said Jayalalithaa wrote a letter to late MGR complaining that Kamal Hassan had not given adequate publicity in the media to him (MGR), who had participated in a special show of a film for raising funds.
Reacting to Mr Karunanidhi's charge, Jayalalithaa on Thursday said when MGR was the Chief Minister she was the propaganda secretary of the party and used to meet and discuss every day.
There was no need for her to write a letter when she can discuss with the late leader directly.
"Since Karunanidhi has made a fantastic charge, it cannot be dismissed lightly. So we will be instituting legal proceedings against Mr Karunanidhi", Jayalalithaa told reporters early in the day.