The CID slapped murder charges on Jagannath Sarkar, BJP MP from Ranaghat, in its supplementary chargesheet before the additional chief judicial magistrate’s court here on Monday, related to the 2019 murder of Trinamul MLA Satyajit Biswas.

An investigating officer of the CID said: “The MP (Sarkar) has been found involved in a conspiracy behind the murder of the MLA. We have also slapped a murder charge against him for his role.”

The officer added that the agency had also termed Sarkar the key conspirator in the supplementary chargesheet.

Assistant public prosecutor of the Ranaghat ACJM court Pradip Pramanik said: “Necessary legal course of action will be initiated against the MP.”

As Trinamul defector to BJP Mukul Roy had also been named in the FIR, there was keen interest in what the CID would say about Roy in its chargesheet. On Monday, the CID sought more time to investigate the role of Roy. The ACJM granted the agency time to do so till December 14.

Krishnaganj MLA Biswas was shot dead on February 9 last year while watching a cultural event on Saraswati Puja near his home in Phulbari, Nadia district.

Five persons, including Roy, had been named in the FIR lodged by Milan Ghosh, Trinamul activist and close friend of Biswas.

The CID took up the case and arrested five persons including prime accused Abhijit Pundari, who allegedly shot the MLA. MP Sarkar’s name had surfaced during the probe.

In May last year, CID submitted the chargesheet against three persons. However, they found nothing against Roy and Sarkar. Eventually, the CID dropped their names from the chargesheet which prompted the original complainant to file a revision appeal urging the court for “further investigation” against the duo. The ADSJ Ranaghat allowed the revision application, but restricted the scope of further investigation against the two leaders. Nevertheless, CID continued to probe by violating the court order, alleged lawyers defending the BJP duo.

Sarkar alleged state government “conspiracy to arrest us before the Assembly polls”. “The motive of the revision petition was clear which eventually got reflected in today's chargesheet. We will fight the battle in court,” he said.