Abdul Rauf Sheikh, an eyewitness in the 2002 case in which an inebriated Khan is alleged to have rammed his car into a bakery in western Mumbai killing one and injuring four, turned hostile in a city court.
Sheikh retracted his earlier statement to police that he saw Khan coming out of the car after the accident.
Of the 60 witnesses in the case, four have already deposed before the court. Among them were Ravindra Patil and Ramasray Pandey, who had witnessed the incident.
Patil was Salman's bodyguard and was with him at the time of the accident while Pandey was sleeping in a shop near the accident site.
All witnesses had earlier supported the prosecution's case.
The change in Sheikh's stance has come as a breather to the star, who was Wednesday issued a show-cause notice by a Rajasthan court for allegedly misleading it in a poaching case.