Hazare had led the 2011 anti-corruption campaign in Delhi to seek introduction of the Jan Lokpal Bill.
"It was because of the anti-corruption fight in Delhi that Kejriwal became the Chief Minister. And today, when he (Kejriwal) is accused of corruption, I cannot tell how deeply sad that makes me," Hazare said.
The social activist said he will talk in detail after studying the accusation made by Mishra.
Mishra, who was sacked on Saturday as minister, said: "Day before yesterday (Friday), I saw Jain hand over Rs 2 crore in cash to Kejriwal. When I asked about the money, Kejriwal refused to answer."