The Opposition on Friday accused the BJP of receiving crores in donation from a company being probed by the ED for allegedly buying properties from Iqbal Mirchi, an accused in the 1993 Mumbai bomb blasts, and asked whether or not it was a case of "treason".
Congress's chief spokesperson Randeep Surjewala cited a media report which claimed that the BJP took a large donation from a firm being probed by the Enforcement Directorate for carrying out transactions with and buying properties from the late Mirchi.
The Communist Party of India also stepped up its attack on the party and said it has been "exposed".
There was no immediate response from the BJP on the allegations.
The attack on the BJP came after news portal The Wire reported that it had received large donation from a company being probed by the ED for facilitating "terror funding", citing the ruling party's filings with the Election Commission.
The report said the company, which was involved in transactions with and buying properties from the late Iqbal Memon alias Iqbal Mirchi, gave Rs 10 crore to the BJP in 2014-15. Mirchi was a close aide of Dawood Ibrahim.
"BJP's 'donation saga' gets murkier -- Electoral Bond Scam to donations from accused of 'terror funding'! Why did BJP receive Crores in donation from a Company accused of buying properties of Iqbal Mirchi, a Dawood Ibrahim aide? Is this not 'treason' Mr Amit Shah?" Surjewala asked in a tweet.
With "links to Iqbal Mirchi, terror funding companies and a litany of organisation being investigated by the Enforcement Directorate, the BJP's electoral bond scandal may have crossed over from corruption to treason", the Congress added in a series of posts from its official Twitter handle.
The Congress also demanded an answer on the issue from Prime Minister Narendra Modi and BJP president Amit Shah.
"As it turns out the 'Modi Bond of Corruption' extends to terror funding companies as well. Companies associated with Iqbal Mirchi have donated crore of rupees to the BJP. PM Modi and Amit Shah must answer on these treasonous acts," the party said.
Terror accused Mirchi is directly connected to three companies that have donated money to the BJP through their dubious electoral bonds scheme, the Congress said.
"Why did BJP accept money from companies linked to terrorists? The PM & HM must answer," the party said in a tweet.
CPI(M) general secretary Sitaram Yechury accused the BJP of making money from those "abetting terrorism".
"Such is BJP's perfidy. BJP milchs the fight against terror to whip up communal nationalist jingoism for electoral profit. Then fills it's coffers with money from those abetting terrorism," he tweeted.
CPI general secretary D Raja said the prime minister needs to explain how "dirty money" or "terror money" could be received as donation by the BJP.
"It is no less than terror funding. During demonetisation, Modi screamed that the move was to curb terror funding, then how does he justify receiving the dirty money from a firm linked to a terror accused?" Raja said.
It is the BJP which has consistently supported donations to political parties from corporates, he alleged.
"They have been taking money from various sources without showing any account. They have now been exposed," the CPI leader said.
The Congress has also stepped up its attack on the Centre over electoral bonds, alleging that the government is a "factory of lies" and demanded that Modi break his silence over the issue.