Singh, who had yesterday questioned Anna Hazare on why he was not attacking the BJP, enclosed a letter from RSS general secretary Suresh (Bhayya) Joshi to him, extending "full support" in his battle against corruption.
In the letter, Joshi had informed Hazare that in the RSS executive committee meeting held in March serious concern was voiced over the issue of corruption and the RSS "gives full support to your efforts against corruption".
In the brief letter, the Congress general secretary wondered as to how Anna has not read the letter. "If you have not read the letter, then it is a more serious matter, as I have already said that people close to you are keeping you away from the actual situation," he said.
The letter has come on the eve of the Hisar Lok Sabha bypolls, where Team Anna is campaigning against the Congress.
In his letter yesterday, Digvijay Singh had also cautioned Hazare against "lofty promises" by that party of making him a Presidential candidate.
Singh had asked Hazare why he was "silent" on the issue of corruption when the BJP-led NDA was in power. He had told Hazare that an impression was gaining ground that he has been surrounded by people who have always been opposed to the ideology of the Congress.
"Be it Shanti Bhushan or his son Prashant or your colleague Arvind Kejriwal. All these people have been opposed to the Congress. These people are taking benefit of your clean character for their own political gains," he had said attacking Team Anna members.