The Central Bureau of Investigation has sought the tapes of the telephonic conversation between Bollywood stars Salman Khan and Aishwarya Rai, tapped by the Mumbai police in 2001, in connection with its probe into the 1993 Mumbai serial blasts, sources in the investigating agency said.

The CBI asked the Mumbai police to give it a copy of the tapes in which Salman purportedly said that he had advance information about the 1993 serial blasts, said the sources. The voice samples of actors Salman Khan and Aishwarya Rai were also sent to a forensic laboratory in Chandigarh to compare them with the voices figuring in a tape of the alleged telephonic talk between the two in which Salman purportedly boasted of his underworld connections, police sources said.

The voice samples of Salman and Aishwarya were taken by police in furtherance to a probe ordered by the Maharashtra government to ascertain the genuineness of the tape.

The Salman-Aishwarya tape had created uproarious scenes in the Assembly with the Opposition grilling the government on the issue for not taking action against the actor and the government assuring that probe had been ordered and it would make a statement on the floor of the House.

Besides the actors, police has also recorded statements of four top officers, namely inspectors Pradeep Sharma, P Bhandari, Ashok Borkar and sub-inspector Daya Nayak, in connection with the ongoing tape probe, to know if they were aware of existence of such a tape, the sources said.

Police also recorded the statement of former crime branch DCP Pradip Sawant, who was one of the senior most officers in Mumbai Crime Branch when the alleged conversation between the two stars is believed to have been recorded in 2001.

The audio tape, whose contents were aired by television channels and transcripts published by a newspaper has Khan flaunting his underworld connections and asked Rai to perform in a show organised by gangster Abu Salem, warning her of dire consequences if she refuses.