"Chidambaramji, you are the country's finance minister, such a big scam has taken place who are you trying to save? Why have Mamataji and Chidambaram joined hands to help those responsible for the Saradha scam, people of Bengal want to know," Modi said at an election rally here in Hooghly district.
Who has bought Mamata Banerjee's painting for Rs 1.8 crore, asked Modi
Seeking to assure the victims of the Saradha scam in states like Bengal, Jharkhand and Odhisa, he said: "I announce that after forming the government in Delhi, strong action will be taken on this issue. Nobody will be spared."
Attacking Banerjee, Modi raised questions about one of her paintings being sold for Rs 1.80 crore.
Bengal's opposition parties have been alleging that purported Saradha scam mastermind Sudipta Sen had bought the painting at the exorbitant price.
"Some people have brought a matter before me. I am publicly drawing your (Mamata) attention to this. Your image is being besmirched for this. This is not good for you, for the country's democracy. So it is my responsibility that I bring this issue to your notice," said Modi.
"You are a good painter. I have heard earlier your paintings used to be sold for Rs.4 lakh, Rs. 8 lakh, Rs.15 lakh. But what is the reason behind your painting once being sold for Rs.1.80 crore."
Dripping sarcasm, Modi said the country is proud to have such a painter, but questioned who who purchased the painting?
"How many paintings did he buy? Who all have bought your paintings?? And at what prices? People of Bengal want to know.
"People of Bengal, known for their dedication to arts, will not tolerate if work of art is sold off to thieves and looters."
Accusing Banerjee of having "shattered the dreams" of the peole of Bengal, who had showered their love on her, Modi said: "Mamataji, this was not expected of you."
Opposition parties in the state have targeted the Banerjee-led Trinamool on the scandal, which has been hogging the limelight in the campaign after the Enforcement Directorate recently arrested purported scam mastermind Sudipta Sen's wife and son and quizzed a Trinamool Lok Saha poll candidate.
The Saradha scam -- the biggest such scandal to hit the state -- came to light in April last year when the company closed shop across Bengal, unable to pay back depositors, many of whom were from poorer sections of society.
As the company went bust, many agents and investors committed suicide, and protests took place across the state. Trinamool MP Kunal Ghosh is in jail for his alleged involvement in the scandal.