Mumbai, Aug 6 (IANS): The CBI on Friday filed a supplementary chargesheet against extradited mafia don Chhota Rajan Nikhalje and another person for the 2011 killing of journalist Jyotirmoy Dey, an official said here.

The supplementary chargesheet was lodged before the Special MCOCA Court, as per the court's directions to comply by August 5.

The development took place after the CBI took over all the cases related to Chhota Rajan and lodged a first information report (FIR) for murder, conspiracy and other charges against him after his extradition from Indonesia on October 25 last year.

The CBI said that after using advanced scientific techniques and voice samples of the accused it unearthed the conspiracy to kill Dey.

"Sufficent evidence has also emerged to establish that global roaming SIM cards were arranged by the accomplice to the members of the organised crime syndicates," the CBI said.

Chhota Rajan has been named as the key conspirator at whose behest Dey was gunned down near his home in Mumbai by two motorcycle borne gunmen in June 2011.

Earlier, in December 2011, the Mumbai Police had also lodged a chargesheet against Chhota Rajan - who was an absconder at that time -- and his associates under the stringent MCOCA.

It has been alleged that the mafia don was irked by Dey's crime stories and allegedly plotted to eliminate him.

During the investigations, the Mumbai Police nabbed 10 accused including a Mumbai journalist Jigna Vora. She was charged with instigating the killing owing to professional rivalry.

In June 2015 the Special MCOCA Court framed charges against all the accsued.

They include: Rohith Joseph alias Satish Kalia, who allegedly fired at Dey from close range, Anil Waghmode, Nilesh Shedge, Abhijit Shinde, Arun Dake, Sachin Gaikwad, Deepak Sisodia, Joseph Paulson and Mangesh Agwane.

Another wanted accused, Nayansingh Bisht, had allegedly procured the weapon used in the crime but is absconding.

A local builder, Vinod Asrani, who had allegedly pinpointed Dey to the killers, passed away due to natural causes sometime ago.

Chhota Rajan is facing around 70 cases in Maharashtra including the Dey murder case.

A veteran crime reporter, Dey was the Investigtions Editor of Mid-Day tabloid when he was gunned down.