Besides Bhattacharya and Khan, Prasanta Pramanik - the president of the Majhi & Dari Workers Union Dakshineswar - too reached the CBI office for questioning about alleged links with the scam.
Khan, whose house was raided by the CBI Aug 29, has alleged involvement of his own party leaders in the scam.
"Some of these leaders, who had to go to sleep without food, have now amassed assets worth Rs.500 crore to Rs.1,000 crore. I do not know who gave them the money or from where it was accumulated," Khan said earlier in the week.
With the CBI making steady headway in the case, the Trinamool has accused the agency of being "politically used".
The agency has already grilled Bapi Karim, a former confidential assistant to West Bengal Sports and Transport Minister and Trinamool Congress leader Madan Mitra.
Besides, it again took the custody of suspended Trinamool MP Kunal Ghosh.
Ghosh, who has repeatedly alleged the involvement of the Trinamool top leadership, Saturday dropped a bombshell saying he should be jointly interrogated with Chief Minister Mamata Banerjee and scam kingpin Sudipta Sen.
Meanwhile, Ghosh Sunday alleged that Trinamool secretary general Partha Chatterjee and party leader in the Lok Sabha Sudip Bandyopadhyay had travelled to New Delhi for the inauguration of Saradha's media foray.
Ghosh made these allegations outside the Salt Lake CGO complex when he was being whisked out by CBI officers.