"Concerned ministers, party president have answered. For each silly issue asking the PM to answer is not fair," Mr Gowda said, adding, "the state has initiated a probe, deaths are a matter of concern. But law and order is a state subject".

His comments came soon after Congress leader Digvijay Singh, a former Madhya Pradesh chief minister, said, "PM stays silent on these issues and tweets on Tunisia, Syria... Now he is on a Central Asia tour... I think from now on he will stay abroad."

A little while later, Madhya Pradesh chief minister Shivraj Singh Chouhan announced at a press conference that he is requesting the state's High Court to order a CBI inquiry into the Vyapam scam and the deaths linked to it.

Mr Chouhan had so far refused to recommend a CBI inquiry, saying only the state High Court, which is monitoring the current investigation by the state police, could decide on ordering one.

Digvijaya Singh is among four people who had also filed petitions in the Supreme Court for a CBI inquiry into the scam. The Supreme Court had this morning agreed to hear the petitions on Thursday.

On Thursday, the Supreme Court is also scheduled to hear a petition filed by a group of lawyers from Gwalior, who have sought the removal of Madhya Pradesh Governor Ram Naresh Yadav, earlier named in the scam, to ensure a fair inquiry.

The Congress in Madhya Pradesh has also demanded Mr Chouhan's resignation to ensure an impartial inquiry.

On Monday, the party linked the death of a police constable in Madhya Pradesh to the Vyapam scam. The constable Ramakant Pande was found hanging from a ceiling fan in his Orchhca home. The police has denied reports that he had been questioned in the scam.

The death of a trainee sub-inspector too has been linked by the Congress to the scam. The body of Anamika Kushwaha was found in a lake on Monday morning. The police has said both Ms Kushwaha and Mr Pande committed suicide.