NEW DELHI (Reuters Life!) - Bollywood bad boy Sanjay Dutt is to portray Charles Sobhraj, an infamous killer nicknamed "the serpent" for his ability to give police the slip, in a new film.

Sobhraj, 63, currently serving a life term in a jail in Nepal for the murder of an American backpacker, was arrested in 2003 at a casino in Kathmandu. He has appealed against the verdict.

A suave, smooth-talking operator, Sobhraj is accused of killing more than 20 young western backpackers across Asia, usually by drugging them, in the 1970s and 1980s. His exploits spawned two books, a movie and many articles.

Now Dutt, convicted last year in connection with India's worst bombing, will try to get under the skin of Sobhraj's character.

Dutt, 48, a beefy action hero, is out on bail while he challenges his conviction for receiving illegal guns from gangsters.

The new film, "Charles and I", will focus on the years of cat and mouse that Sobhraj played with the law. It will be shot in Turkey, France, India and Australia, director Prawaal Raman told Reuters on Thursday.

"This is going to be a very interesting film and I have done extensive research and interviewed the police officers who arrested Sobhraj in India and handled his case," Raman said from Mumbai.

"He is a most fascinating person and was an enigma for the police."

A master of disguise who escaped from various jails around the world, Sobhraj was born to an Indian father and Vietnamese mother. He is a French national.

Serving a 20-year sentence in India, he escaped from prison in the mid-1980s, but was caught and returned to jail until 1997 when he was released.

In 1975, Thailand issued a warrant for his arrest on charges of drugging and killing six women, all wearing bikinis, on a beach at Pattaya. But he was jailed in India before he could stand trial on those charges.

In the new movie, a police officer narrates the tale of Sobhraj, and discusses his modus operandi, the director said.

But Sobhraj's lawyer said no film director had sought permission to make a film on his life.

"Without his permission it cannot be made," lawyer Raja Ram said.

The film will be released early next year, Raman added.