"First he (Rajan) gave his consent (for the voice test) but later he refused to undergo the same," CBI prosecutor Bharat Badami told the court after the fugitive was produced before it via video-link from Tihar jail.
On the CBI plea, Special Judge S S Adkar asked Rajan's advocate Anshuman Sinha to file a reply. The matter is likely to come up for hearing on February 11.
CBI told the court that an audio CD containing telephonic conversation between Rajan and a person has been deposited in the court by Mumbai Police and they want to compare the voice in the CD with that of Rajan.
Badami also sought more time for investigation into the murder, saying that they need to take help of some external agencies like Interpol to probe the case against Rajan as he was out of country for long following which its prayer was granted.
CBI also said that the mobile of Dey, the murdered journalist, has not been sent yet for any forensic test and pleaded to the court to handover the mobile to the agency for its examination at CFSL in New Delhi.
The central agency also requested the court that two laptops and one computer hard disk of Dey may also be handed over to CBI for further forensic examination for retrieval of deleted data.
On January 19, the court had allowed CBI's plea seeking a nod to question the 54-year-old crime boss for 10 days starting January 27 before adjourning the case till today.
Rajan, a former key aide and lieutenant-turned-bête noire of underworld don Dawood Ibrahim, was arrested at Bali airport in Indonesia on October 25 after he arrived from Australia, and was later deported to India.
He is facing around 70 cases in Maharashtra, including the J Dey murder case. The Maharashtra government has handed over all the cases against him to CBI.
Dey, a veteran crime reporter, was shot dead in suburban Powai by motorcycle-borne shooters on June 11, 2011 allegedly at the behest of Rajan. Four persons on two motorbikes fired at least four to five rounds at Dey, who was also riding a bike, from behind near Spectra Building at D Mart in Hiranandani area of Powai.