At a crowded press conference in Lucknow, an angry Siddiqui claimed that he had enough material to cause an "earthquake".
Mayawati had expelled Siddiqui and his son Afzal on Wednesday, accusing him of involvement in anti-party activities.
Siddiqui said he was in possession of 150 such audio clippings.
"I have served the party with my sweat and blood only to be expelled for failing to fulfil Mayawati's monetary demands", he stated adding, "I was not allowed to go for the burial of my daughter as I was the poll agent of Mayawati who was fighting election from Badaun". After claiming he was asked to arrange money by selling his properties he said she said, "It will help your career in future".
Siddiqui played six audio clippings of his phone conversations with Mayawati to support his allegation that money had been demanded from him. That he refused to hand it over is one of the reasons he was expelled.
Mishra alleged that Siddiqui was involved in "anti-party activities" and had taken money from candidates during the assembly elections in which the BSP's tally fell to an all-time low of 19.
Siddiqui said after the Samajwadi Party (SP) and the Congress cobbled an alliance ahead of the February-March assembly election, he told Mayawati that the Muslims were drifting towards the alliance.
Hours after he and his son, Afzal, were shown the door by the party, Naseemuddin said, "Whatever charges have been levelled against me, applies to her (Mayawati) and I can prove those with evidence". Mayawati also said Siddiqui, who was expelled on Wednesday for "anti-party activities", can not be trusted with the party's responsibilities because he "recorded her calls and tampered them".
She did not even give me an audience to explain whatever was said against me, he said.
"BSP workers say ever since I made my younger brother vice president, he (Naseemuddin) was very perturbed as he used to claim he was number two in the party.I had to bring my brother in the party as we need honest people not selfish ones".
BSP is totally under the grip of Mishra and company, Mayawati is being blackmailed by them, he claimed. When Mayawati formed the government with full majority in 2007, Naseemuddin was given the charge of around a dozen departments including PWD and excise.
With a view to revamp her party, Mayawati had also dissolved the existing team of zonal, divisional and district coordinators and brotherhood committees set up to woo different castes and communities like Brahmins, Thakur and Muslims.
Meanwhile, the BSP chief on Thursday, said that Siddiqui was made in-charge of western UP during the election but she got complaints from people alleging that he was a "blackmailer".