"I am supporting her but I am not supporting any political party," he said without elaborating.
Hazare said he was supporting Banerjee as she agreed to implement his "17 point agenda" covering a range of issues including containing graft and bringing in more transparency if she comes to power at the Centre.
"I will not support any party, even after 2014 elections. I just want to serve my country and will support anybody who makes similar efforts, but will not support any political outfit," he said.
Among other issues in the 17-point agenda of Hazare are land acquisition, FDI in retail, judicial accountability bill and bringing back black money.
"The 17 points that I mentioned are powerful points and if implemented they will bring breakthrough changes in our country," he said.
Hazare refused to reply to a question on who among Banerjee, Arvind Kejriwal and Narendra Modi will be the best leader for the country.
The social activist was speaking after releasing a book titled "Is it police: Confessions of a top cop", written by Vinoy Kumar Singh, an IPS officer of 1987 batch from Andhra Pradesh cadre. Singh is currently posted as ADG of police in Hyderabad.
Also present on the occasion was former Delhi Police Commissioner Neeraj Kumar.
When asked whether he has any plans of joining politics, Kumar said, "I would like to keep that option open. I haven't considered it yet but if any offer like that comes my way, I will think about it."
In his book, Vinoy has chronicled over 23 years of his experiences as a police officer and highlighted few "negative" aspects of the profession.