It added that in most of the documents recovered from him, Rajan had used the name of Mohan Kumar.
An SMS was purportedly sent from the cell phone of Chhota Shakeel, a close aide of fugutive mob boss Dawood Ibrahim, to a senior Tihar jail official threatening to eliminate Chhota Rajan.
CBI sources said the first case relates to Bhendi Bazar shoot out allegedly executed by hired shooters of Rajan in February 2010 in which two persons were killed.
The CBI is facing a staff crunch and had written to the state government for assistance.
The court has granted conditional bail, directing the accused not to leave the country without its permission.
Asked by the court about the progress in its investigation, the agency replied that it was yet to appoint a prosecutor.
Dey, a veteran crime reporter, was shot dead in suburban Powai by motorcycle-borne shooters on June 11, 2011 allegedly at the behest of Chhota Rajan.
CBI sources said the agency has charged them with criminal conspiracy, cheating, forgery and under Provisions of Prevention of Corruption Act in the charge sheet.
Judge A L Pansare of the Maharashtra Control of Organised Crime Act (MCOCA) court allowed an application filed by the CBI seeking permission to quiz Rajan.
Former Delhi police commissioner says that the former Dawood Ibrahim’s aide enjoys a special relationship with the government.
Rajan, who was brought to India in October after being detained in Bali, was produced in the MCOCA court in Arthur Road Jail through video-conferencing from Tihar jail Thursday.
Rajan was arrested at Bali airport in Indonesia on October 25 last year after he arrived there from Australia.
Ramnarayan Gupta alias Lakhan Bhaiya, an alleged Chhota Rajan gang member, was killed in a fake encounter on November 11, 2006 in Versova.
The state government had issued a notification earlier, transferring the cases to the CBI, and assured the central agency that it would depute officers, if necessary, to assist it in the matter.
Rajan, who was recently caught and deported from Indonesia, is a wanted accused in this case.