"The CBI is the Prime Minister's department, nothing happens without his orders," Mamata alleged.
She was addressing a public rally for the April 18 Kolkata Municipal Corporation elections at Beliaghata here.
"It has not sent notice to any other party in the country, so why has it sent to us?" the Trinamool Congress supremo asked, alleging a "political vendetta" by the BJP.
"It has been done as the Trinamool Congress is the only party which can take on the BJP," she claimed.
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"They cannot fight us politically, so they are using CBI," she said, claiming, such issues cropped up only before elections and then died down.
"As the KMC election is nearing, they (BJP) have started to make issues out of non-issues, I can tell these things will again crop up before the 2016 Assembly elections in the state," she said on the CBI's recent notice to the TMC All-India General Secretary Subrata Bakshi to furnish details of its accounts.
Bakshi replaced Mukul Roy, once the most-trusted aide of Banerjee, as the party's all-India general secretary in mid-February, after Roy fell out of favour with the party's supremo.
"Those who have spent unlimited funds for Lok Sabha elections are questioning Trinamool Congress' income," she alleged.