"It is unjustified. Apology for what? If R R Patil says he has no record of the call, what is wrong in it," party general secretary D P Tripathi said.
Tripathi`s comments came after Singh released records of the conversation the slain ATS chief had with him on 26/11.
"People called me a liar...I was dubbed a traitor and a Pakistani agent. It pained me that Mumbai Police made selective leaks saying that there were no records of the talks between me and Karkare."
"It was all the more painful for me when the Maharashtra Home Minister said in the state Assembly that no such call was made. All those who have dubbed me a liar and have put a question mark on my honesty, sincerity and credibility should apologise or at least express regrets now when I have produced documents," Singh said.
In a letter to Patil, he said, "I am very pained by the statements made by you and the Mumbai Police. I request you to make a public apology or express regret".
The Congress leader expressed anguish that these statements were used by the media to prove him false and declare him a "liar". "If you or Mumbai Police had properly examined the number of Maharashtra ATS, you would not have given such a statement."
Raising doubts over his claims, Patil had then said there was no existence of any record of the purported telephonic conversation between the Congress leader and Karkare.