"Ashwini Kumar, who as a minister tried to interfere in the dispensation of justice and also interfered in the course of investigation, must wither resign or should be sacked by the Prime Minister," party leader Balbir Punj told reporters here.
He demanded that an SIT be constituted directly under the Supreme Court to investigate the "massive scam where the needle of suspicion points out even to the Prime Minister".
"The government has absolutely no qualms in pressuring the CBI so that the accused persons go scot free... In order to sabotage the dispensation of justice," Punj said.
CPI(M) demanded that "government must come out with what actually transpired and who are the persons involved in the matter".
Appropriate action should be taken against those involved in the charges of interfering with the course of justice, the party said in a statement.
It said the latest instance of the government misuse of the CBI reinforces the case for "strengthening CBI's autonomy and the need for parliamentary oversight.