NEW DELHI: Senior Trinamool Congress (TMC) MLA Sovandeb Chattopadhyay on Saturday assured full cooperation with the West Bengal CID’s probe into the alleged signature forgery case, but maintained that others who were present at the time should also be questioned.His remarks came after he was questioned for over an hour by a two-member team of the state’s Criminal Investigation Department at his residence in Kolkata’s Bhawanipur, PTI reported.“I will cooperate with the probe more than 200%. But those who made the allegations of signature forgery should also be questioned, because everyone was present when the proposal was signed,” the Ballygunge MLA told reporters.The controversy revolves around a letter submitted to assembly Speaker Rathindra Bose by the Trinamool faction led by its supremo and former chief minister Mamata Banerjee, proposing Sovandeb Chattopadhyay as leader of the opposition. The letter reportedly carried the signature of TMC national general secretary Abhishek Banerjee, Mamata Banerjee’s nephew.The Speaker, however, declined to accept the communication after allegations emerged that signatures on the document had been forged.The complaint was lodged by legislators Ritabrata Banerjee and Sandipan Saha, both of whom were later expelled from the party.Escalating the leadership tussle, Ritabrata subsequently submitted another letter claiming the support of 59 MLAs and was eventually recognised by the Speaker as leader of the opposition. The TMC secured 80 seats in the april Assembly elections, ending its 15-year tenure in power.The new BJP-led state government later handed the alleged forgery case to the Criminal Investigation Department for investigation.As part of the probe, CID officers have questioned Abhishek Banerjee multiple times and collected handwriting samples from several TMC legislators. While some MLAs have been served notices, others have been questioned at their residences.On Friday, CID officers visited the residence of senior TMC MP Kalyan Banerjee to serve a notice in connection with the case. The notice could not be delivered as he was in Delhi and his family members declined to accept it.The investigation has unfolded alongside a legal battle over the opposition leadership in the Assembly. Chattopadhyay moved the Calcutta High Court challenging the Speaker’s decision to recognise Ritabrata Banerjee as Leader of the Opposition, but a single bench declined to grant interim relief.He has since approached a division bench against the order, with the matter expected to be heard next week.