The Central Bureau of Investigation (CBI) has registered an FIR in the alleged murder of West Bengal Chief Minister Suvendu Adhikari's aide Chandranath Rath, taking over the investigation from the state police.
The CBI took over the probe following a request from the state government, officials said.
According to the procedure, the CBI re-registers the state police FIR as its own case, which becomes the starting point for the probe.
The investigation is conducted independently, and the outcome may or may not support the allegations.
The CBI then files a final report before a competent court, which can be a chargesheet or a closure depending on the findings of the agency.
Three people were arrested from Uttar Pradesh and Bihar in connection with Rath's killing, pursuing leads from a UPI transaction made at a toll plaza by one of the suspects.
Rath, the executive assistant to Adhikari, was shot dead in Madhyamgram on May 6, two days after the declaration of the fiercely fought West Bengal Assembly Polls results.
The incident took place on a public road at Doharia in Madhyamgram area.
Rath sustained critical injuries in the firing and was rushed to a private hospital, where doctors declared him dead.
At least eight people were involved in the conspiracy and execution of the murder, officials said.
