The prosecution in the hit-and-run case involving actor Salman Khan [Images] has received a setback with four key witnesses disappearing from their homes and not being available for deposition.

Efforts are being made to trace them, the prosecution informed the trial court on Thursday.

They were not available at their homes and have perhaps shifted elsewhere, the prosecutor told the court.

The four witnesses are considered significant to the prosecution's case as they were injured by the actor when he had allegedly rammed his car into a pavement on September 28, 2002.

Salman had rammed his car into a bakery in suburban Bandra killing one person and injuring four others who were sleeping on pavement on the ill-fated day.

The court has deferred the trial to June 29, according to Salman's lawyer Dipesh Mehta.

Of the 60 witnesses, 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 had accompanied him when the actor met with an accident while Pandey was sleeping in a shop adjacent to the accident site. Both have dwelt upon the accident in their evidence.

The other two witnesses are panch witnesses who have prepared the panchnama at the site of the accident and the panchnama of the body of the person who was killed in the mishap respectively. All the witnesses have supported the prosecution's case.