Almost 40 years after one of Bollywood's most famous films broke box office records, "Sholay" (Embers) has been restored for release Friday in 3D to a new generation of moviegoers.

The iconic Indian film, which stars Amitabh Bachchan, Dharmendra, Amjad Khan and other Bollywood greats, is an action adventure about two petty thieves hired by a police officer to exact revenge on a ruthless bandit.

The movie, which borrowed heavily from the Westerns of the time, proved so popular after its release in 1975 that it screened for five years at a landmark Mumbai theatre, the longest ever run in India at the time.

Producers Shaan Uttam Singh and Sascha Sippy said they wanted to restore the original film for new generations of movie watchers, while also giving it a 3D boost.

Singh said the technical process took three years to complete, and was estimated to have cost more than $3 million.

"First we scanned and digitised the original negative and then it was restored," Singh told AFP.

The background score was also modernised, while leaving the dialogue untouched. "We pepped up the music a bit to make it sound modern," said Sippy.

"We first had to fill in the negative where there were holes, digitise the film, strip the sound, keep the dialogue, re-record all the sound and music and also convert the film into 3D," Sippy added.

Sholay opens across Indian and United Arab Emirates cinemas on Friday in 2D and 3D. The classic, which, like all Bollywood movies, includes a love story, will be released in other countries later this year.

Legal wrangling

But torturous legal action had threatened to overshadow the release, with the original Sholay's director, Ramesh Sippy, fighting with family members over who owned rights to the film.

Ramesh Sippy lodged court action against his nephew, producer Sascha Sippy, and other family members who run several companies that own the titles to Sholay as well as other Bollywood films.

Those films include some made by Ramesh Sippy's father, G.P Sippy, who was also the producer for the original Sholay and who died in 2007.

Earlier this year, a Mumbai court denied Ramesh Sippy's request for a stay on the new Sholay's release until his rights to the film were restored. Sippy, who has had no involvement in restoring the film, lost an appeal against the court decision earlier this month.

Film critic and author Khalid Mohamed said the original movie was considered one of Bollywood's finest because of the performances of Amjad Khan, who died in 1992, and others under Ramesh Sippy's stellar direction.

Ranked the best Indian film of all time by the British Film Institute in 2002, Sholay was also given the unusual honour of being "maybe the burliest male love story ever made (in India)" by Time magazine in 2010.

The popularity of Sholay also spawned remakes, spoofs and books, while lines from the movie continue to be used by Indian theatre-goers in everyday conversation.

Considered a pioneering Bollywood film at the time, the original Sholay was also the first in India to use a 70mm format which doubled its size on the big screen and was the first Hindi-language film to be recorded in stereophonic sound.

Sascha Sippy hinted at a sequel saying there was "an idea to reboot the entire franchise - with a prequel and sequel - but these have to be discussed." - by Udita Jhunjhunwala