"Kejriwal is levelling allegations of corruption because there are evidences to support them," Singh told reporters on Thursday but refused to be part of IAC.
"Loknayak Jayprakash Narayan had not joined any party ... He had moved ahead alone to fight corruption and people rallied behind him which resulted in a people's movement in 1974," he said in reply to a question whether he was interested in joining any political party.
"I will tell you about my next step later," the former Army chief said, adding, he would however support any campaign against corruption.
He said he was now working among farmers, youths and jawans to help create a 'janjagran' (people's movement) against corruption.
Singh was here enroute to Ara where he would participate in 'Jawan Kisan Morcha' later in the day.
Earlier, he held meeting with a delegation of ex-soldiers based in Buxar and appealed to them to join peoples movement against corruption.