The letter said the agency can proceed only when it gets enough evidence which is legally tenable.
Singh had alleged tardy probe in select high profile corruption cases including of disproportionate assets against Mayawati and Yadav.
In his letter to CBI Director Ranjit Sinha, Singh alleged that the investigating agency was “dragging its feet” in many cases.
“We are, however, dismayed with the functioning of the CBI in quite a few cases, in which the organisation has played it cool to the extent of dragging its feet. On the other hand, there have been cases where the organisation has been over enthusiastic,” it said.
