"It (CBI) is purely and completely impartial and does not entertain pressure from any influential person," Singh told reporters here.
The Congress leader said it was due to CBI's "impartial" character that the party had "suffered immensely".
He said CBI sleuths picked up accused only after complete information regarding the wrongdoings of the person.
Singh's defence comes in the backdrop of UP Chief Minister Akhilesh Yadav's recent attack against Congress, alleging that anybody who does not act according to its wishes faces "persecution" through CBI.
The minister, in reply to media questions regarding increasing crime against women, said in 96 per cent of such cases it was found that victims and attackers were known to each other.
