Kolkata, Sep 10 (IANS): Facing the heat over the alleged involvement of its leaders in the Saradha scam, West Bengal's ruling Trinamool Congress Wednesday accused the Narendra Modi-led central government of using the CBI as a pawn.

In the wake of the Central Bureau of Investigation (CBI) arresting Trinamool vice president and former IPS officer Rajat Majumdar and grilling its MP Srinjoy Bose, the Mamata Banerjee-led party questioned the credibility of the central agency.

Addressing a press conference here, Panchayat Minister Subrata Mukherjee and Trinamool secretary general Partha Chatterjee lashed out at a section of the media for running a smear campaign against the party.

"The CBI is being used as a pawn to settle political scores by the ruling party (at the centre). A deep conspiracy has been hatched to defame Mamata Banerjee, whose credibility is beyond question," said Mukherjee.

"If CBI performs its duties in a bipartisan manner, we will welcome it. But we will not tolerate the CBI being used for political purpose. We believe in healthy politics," added Mukherjee.

Chatterjee, also the state education minister, accused the BJP of using the CBI to derive political gains with an eye to the Sep 13 by-polls in Basirhat South and Chowringhee assembly constituencies.

"The BJP is indulging in a dirty political game, using the CBI, ahead of the by-polls. The credibility of CBI is under question now," said Chatterjee, who charged a media house with conspiring alongside the BJP.

Claiming that the chit fund companies evolved and flourished during the erstwhile Left Front government, Chatterjee demanded that all such chit fund companies, right from 1980 to 2012, should be investigated and the perpetrators be punished.

The Trinamool, which has fought tooth and nail legal battles to keep the CBI away from probing the scam, has been questioning the agency's role ever since the Supreme Court directed it to take over the reins of the investigation from police.