"We take as genuine the Congress president's reply to Anna Hazare's letter. But she should take action if Digvijay Singh speaks just the opposite to what she said in her reply," Agnivesh told newsmen here.
Gandhi had assured Hazare that she did not support smear campaigns and reiterated her commitment to fighting corruption.
"But if she does not rein in Digvijay Singh's statements, it will look like ''run with the hare and hunt with the hound''. This will spoil the image of the party and will be a big loss to it," he added.
The social activist visited the demolition sites in Ranchi following the anti-encroachment drive taken up by the district administration in the wake of high court's order to implement its earlier orders passed in 2003 and 2006 against encroachment.