"We request the Chief Minister to let the CBI investigate the case, so that the truth comes out. We want to know the facts and want the culprits to be arrested. The police has no capacity to make arrests in this case," Sinha told reporters here.
Farzana, who had died last month following a heart attack, was allegedly at the receiving end of a faction of the Trinamool Congress.
The BJP leader pointed out that Farzana's death was mysterious because the police had registered a case filed by her kins, but no arrests had been made.
The BJP also announced that it will organise a law violation programme on June 18 to protest against violence and "breakdown of law and order" in the state.
"We will bring out a rally from College Street and organise a law violation program on Rani Rashmoni Road. This will be our protest against the 'Gundaraj' of Trinamool Congress and the breakdown of law and order in the state," the party leader said.