Saradha scam kingpin Sudipta Sen Monday denied purchasing any artworks of West Bengal Chief Minister Mamata Banerjee even as the BJP and Trinamool Congress continued to spar over the alleged sale of her paintings for an exorbitant price.

Sen, now behind bars for the scam, told mediapersons during one of his court appearances that the painting was not bought for any money, but subsequently claimed that he did make any such purchase.

"The painting was not bought for any money," said Sen, to queries at what price the painting was purchased.

However, when prodded further, he said: "I don't know about any such purchase of painting, I did not purchase any painting."

Launching a scathing attack on the Banerjee regime over the Saradha scam, Bharatiya Janata Party prime ministerial nominee Narendra Modi Sunday raised questions about one of Banerjee paintings being sold for Rs.1.80 crore.

Bengal's opposition parties especially the Communist Party of India-Marxist have been alleging that Sen had bought the painting at the exorbitant price.

Modi's remark prompted the Trinamool to unleash a vicious attack as it sought a public apology from him threatening with a defamation suit.

If Trinamool Rajya Sabha member Derek O'Brien called Modi the ""Butcher of Gujarat", party spokesperson Amit Mitra said his "hands were stained with the blood of riots in Gujarat".

Reacting to Sen's denial, CPI-M leader Sujon Chakraborty said Banerjee should come clean about the sale of her paintings.

"She claims that she runs her party selling her paintings, but despite our repeated requests, she never bothered to give details about who buys her paintings and for what amount," said Chakraborty.

Congress leader O.P. Mishra alleged complicity between Sen and the Trinamool and said only a probe by the Central Bureau of Investigation (CBI) can unravel the truth.