"People in this country respect the judiciary the most. Our judiciary is independent and nothing can be more serious than raising questions on it," said Congress Delhi chief Arvinder Singh Lovely.
"Whether a department like law should be headed by a person who is himself accused of breaking the law is a matter of concern," he added.
According to media report, an order was passed by then CBI Special Judge Poonam A. Bamba when she pulled up Bharti and his client Pawan Kumar - facing prosecution on corruption charges - after the CBI accused them of influencing a prosecution witness by speaking to him on phone and discussing the case.
Bharti said that it was "erroneous on the part of the judge to call it tampering of evidence" and that he was instead "strengthening evidence" for the case.
Earlier, Chief Minister Arvind Kejriwal defended the minister, saying no tampering of the evidence was done.