The controversial Salman Khan-Aishwarya Rai tape in which the actor is supposed to have exposed his underworld links is fake as the voices in it don't belong to the stars, reliable sources at a forensic laboratory said.

The sources at the Central Forensic Sciences Laboratory (CFSL) said the tape had been sent back to Mumbai Police two days ago after the voices did not match with those of the two Bollywood celebrities.

The tape had been sent here for examination over a month ago after the controversy of the conversation between Salman and Aishwarya erupted in July this year.

The tape was examined by four or five forensic experts and other scientists, the sources said. It was said to have been recorded in 2001, allegedly by Mumbai Police, and a voice purporting to be Salman was heard boasting about his links with gangsters like Chhota Shakeel.

According to the tape, he was heard asking Aishwarya to toe his line failing which he would get her eliminated by his friends from the underworld.

Salman and Aishwarya had refrained from making any comment after transcripts of the tape came out in the media. The tape came to light a couple of days before Salman's film "Maine Pyar Kyon Kiya" was released.

His brother Sohail Khan had openly come out in Salman's defence and said the tape could have been doctored to give a bad name to his star brother.