The Bombay High Court on Thursday overturned Bollywood actor Salman Khan's conviction in a 13-year-old hit-and-run case, scrapping a lower court's sentence of five years in jail for running over a homeless man.

The decision appears to free one of Bollywood's biggest stars from a case that threatened to end a career of portraying bad boys with a heart of gold in dozens of blockbusters.

A Mumbai criminal court had this year found Khan, 49, guilty of culpable homicide, accusing him of losing control of his Toyota Land Cruiser when driving drunk in 2002.

The vehicle rammed into a group of people sleeping on a city sidewalk, killing one and injuring four.

Khan had appealed against the May sentence.

On Thursday, the Bombay High Court ruled that the testimony of the state's star witness was not "wholly reliable", with the judge adding that the prosecution had not been able to prove conclusively that Khan was drunk at the time of the accident.

"The prosecution failed to establish its case on all charges," Justice AR Joshi told a packed courtroom, adding that Khan had been acquitted.

Khan showed little emotion, although his lawyer declared the ruling "a relief".

The story has gripped film-mad India, and Bollywood fans followed every twist of a case that initially saw Khan argue his driver was behind the wheel at the time of the accident.

Many, though, also questioned the reversal of a guilty verdict that prosecution lawyers had said demonstrated the impartiality of India's justice system, by denying exceptions to the rich and famous.

"The arm of the law is long ... but not long enough to touch the rich and powerful," tweeted a commenter on social media who uses the name @tinucherian.

The case is not Khan's first brush with the law. In 2007, he was jailed for nearly a week for shooting an endangered gazelle on a hunting trip in Rajasthan.

He is also on bail in a case over the killing of protected antelopes.

Prosecutors said they had not decided whether to challenge Thursday's verdict.-Reuters