The West Bengal Crime Investigation Department (CID) on Tuesday carried out a search at the Kalighat residence-cum-office of Trinamool Congress chief Mamata Banerjee as part of its investigation into an alleged signature forgery case that has triggered a major political controversy in the state.

The probe relates to allegations that signatures of several Trinamool Congress MLAs were forged on a communication submitted to the Assembly Speaker regarding the selection of senior party leader Sobhandeb Chattopadhyay as the Leader of Opposition.

According to the complaint, two party MLAs, Ritabrata Banerjee and Sandipan Saha, informed the Speaker that no resolution had been adopted at a May 6 meeting as claimed in the official communication. They further alleged that signatures were added later and questioned the authenticity of several entries on the document.

The CID team, accompanied by police personnel, arrived at the premises located at 30B Harish Chatterjee Street in Kolkata. The location serves as both Mamata Banerjee's residence and an important party office. Investigators reportedly conducted the search after seeking information connected to the collection of signatures under scrutiny.

The development comes amid an intensifying investigation that has already seen multiple notices issued to Trinamool Congress national general secretary Abhishek Banerjee. Searches were also conducted at locations linked to him as investigators sought to verify details regarding the process through which the signatures were collected.