Mukul Roy was the only one who spoke to the businessman but did not take cash.

On a day West Bengal Chief Minister Mamata Banerjee said she was not afraid to go to jail if the BJP used the central agencies to arrest her, former party colleague and now BJP leader Mukul Roy appeared before the Central Bureau of Investigation or CBI in Delhi for questioning in the 2016 Narada sting operation that showed several purported Trinamool Congress leaders taking cash from the sting operator posing as a businessman.

Mukul Roy was the only one who spoke to the businessman but did not take cash.

Mukul Roy, a former Trinamool MP, joined the BJP in 2017 and is today a key leader of the party in Bengal.

Mukul Roy's presence at the CBI office was a surprise today. Trinamool MP KD Singh who allegedly funded the sting and Mathew Samuel who conducted it, were earlier scheduled to appear before the CBI today.

Former Trinamool leader Sovan Chatterjee who joined the BJP on August 14 has been summoned to the CBI's Kolkata office on Saturday. So has Trinamool's Arambagh Lok Sabha MP Aporupa Poddar. She has said she will consult her lawyers and appear at the CBI office in Kolkata on Monday, as summoned.

Sovan Chatterjee is silent so far on the Saturday summons. Yesterday, he did not attend a BJP party meeting in Kolkata. State chief Dilip Ghosh said he will seek explanations from all absent BJP leaders.

Mathew Samuel has told news agencies that KD Singh, as a partner-owner of a news magazine where he worked in 2014, had funded the sting operation "to trap Abhishek Banerjee, Trinamool MP and Mamata Banerjee's nephew".

Mr Singh became a Rajya Sabha on a Trinamool ticket in 2010. The party has lately distanced himself from him. He is under investigation not just for Narada links but also for running a suspected Ponzi group.

At a public rally in Kolkata today, Ms Banerjee said, "Today they are calling my brother, tomorrow they will call me. I am ready for that. I am ready to go to jail. But I am not willing to bow my head before BJP's communal politics. If I got to jail, it will be because I am fighting for my country's freedom as my country is no longer free."

Dilip Ghosh, Bengal BJP leader, said, "Why is she talking about her arrest? She must be worried that if Chidambaram can be jailed, then the long arm of law can reach Kalighat too."