A day after being sacked from the cabinet, Aam Aadmi Party legislator Kapil Mishra claimed he saw Delhi Health Minister Satyendar Jain handing out Rs 2 crore to the Chief Minister at his residence.
Mr Mishra also alleged that Jain informed him about "settling land deals worth Rs 50 crore for Kejriwal's relative".
Delhi Congress President Ajay Maken told the media that Mr Mishra's claims were not mere allegations but testimony of an eyewitness warranting initiation of criminal proceedings against Mr Kejriwal.
"Mishra's claim that Kejriwal took Rs 2 crore is not mere allegation rather an affidavit before the public of what he saw. He is saying what he saw as an eyewitness. The Centre, the Anti-Corruption Bureau and the CBI should immediately take action and register an FIR against Kejriwal.
"Kejriwal has no moral right to continue as the Chief Minister. He should immediately resign," said Mr Maken.
He said the AAP, which governs Delhi, was "riddled with corruption".
"Six of the seven AAP ministers including Deputy Chief Minister Manish Sisodia are facing corruption charges," he said.
Mr Maken alleged that the Modi government was reluctant to take action against the Kejriwal government.
"Corruption charges against AAP are nothing new. The Shunglu Committee indicted the AAP government of serious corruption charges but we have seen no action.
"The BJP is very vocal in criticising the Kejriwal government but when it comes to taking action there is a reluctance. The charges made by Mishra are very serious and cannot be dismissed. The Centre has to take action."
Mr Maken said the Congress will launch a signature campaign in Delhi from Tuesday and hand over 10 lakh signatures to Kejriwal as a referendum on the AAP.