New Delhi, March 1: The Congress on Thursday mocked the Narendra Modi government after over multi-crore Punjab National Bank (PNB) fraud in which accused diamond merchant Nirav Modi and his relative Mehul Choksi, owner of Gitanjali Jems, sneaked out of the country. Speaking to the media, Congress chief spokesperson Randeep Singh Surjewala took a dig at PM Modi over his famous 2014 general election slogan  – na khaung, na khaane dunga (Won’t allow anyone to indulge in corruption). “Khaunga, aur khane dunga, aur pack karke le jane dunga. Lagta hai ye sarkaar ka naya nara ho gaya hai. (Will indulge in corruption and let others do the same. This seems to be the new slogan of the government.)” Surjewala said. Also Read - Delhi Sexual Assault Case: BJP Claims 'Lawlessness', Congress Waves Black Flags Outside AIIMS

The remarks came a day after billionaire jeweller Nirav Modi refused to join the CBI investigation in the US $2 billion fraud in Punjab National Bank citing his business engagements, prompting the agency to issue a stern letter asking him to appear before it next week. (Also read: PNB Fraud: Nirav Modi Gives ‘Concrete Repay Plan’, Says Report) Also Read - Remembering Sushma Swaraj: PM Modi Pays Tribute to Forgone Leader Who Was 'India's Voice at World Stage'

In a terse letter, the CBI had “directed” him to approach the Indian mission in the country where he is residing so that immediate arrangement can be made for his travel to India, officials said. Also Read - Kangana Rananut Speaks on Ram Mandir, Says Aparajita Ayodhya Has Real-Life Muslim Characters Who Fought For Ram Temple

The agency has told him that it is mandatory for an accused to join the investigation whenever they are asked to, they said.

He has been asked to appear for questioning next week, they said. (Also readNirav Modi’s Firestar Diamond Files For Bankruptcy in US)

The agency had earlier asked Modi on his official e-mail id to join the investigation related to Rs 12,636 crore scam pertaining to fraudulent issuance of the LoUs and Letters of Credit (LCs) from Brady House branch of PNB in Mumbai in favour of his and his uncle Mehul Choksi’s companies, they said.

In response, Modi refused to join the investigation saying he has businesses abroad because of which he cannot return, they said.

The probe agency officials has said the quantum of the alleged fraud perpetrated in the bank by billionaire jewellers Modi and Choksi stands close to USD 2 billion after the teams of the CBI and PNB found fresh LoUs and LCs worth Rs 1,251 crore related to Choksi’s Gitanjali group of companies.

The PNB had earlier put the defrauded amount at Rs 11,394.02 crore (US $1.77 billion).

The LoU is a guarantee which is given by an issuing bank to Indian banks having branches abroad to grant a short-term credit to the applicant. In case of default, the bank issuing the LoU has to pay the liability to credit giving bank along with accruing interest.

It is alleged that LoUs and LCs worth close to US $2 billion were issued to the companies of uncle-nephew duo of Choksi and Modi from the Brady Road branch of the bank through SWIFT (Society for Worldwide Interbank Financial Telecommunication) messages.

These messages were allegedly not entered in the banking software of the PNB to bypass surveillance.

(With inputs from PTI)