Serial killer The Serpent, Charles Sobhraj, freed from Nepal jail

A French serial killer known as The Serpent, convicted of several tourist murders in Asia in the 1970s, has been released from a Nepalese prison.

Charles Sobhraj, 78, was freed after a court ruled in favour of his age and good behaviour.

He spent 19 years in jail in Nepal for killing two North Americans in 1975.

Sobhraj, whose story was covered in the TV drama The Serpent, had preyed on mostly young Western backpackers on the hippie trail in India and Thailand.

The notorious killer had been concurrently serving two sentences, each 20 years, in Nepal's capital Kathmandu for the 1975 murder of an American woman, Connie Jo Bronzich, and her Canadian backpacker friend, Laurent Carriere.

He had been convicted in two separate trials - most recently in 2014, when he was sentenced to a high security prison for murdering Carriere.

But Nepal's Supreme Court ordered Sobhraj's release on Wednesday after his legal team successfully filed a petition claiming he should be given a concession on his prison term due to health reasons.

A provision in Nepalese law also allows inmates who have shown good character and completed 75% of their jail term to be released.

"Keeping him in the prison continuously is not in line with the prisoner's human rights," the verdict read, according to AFP, and cites regular treatment for heart disease as another factor in his release. He had heart surgery in 2017.

Sobhraj has been linked to more than 20 killings between 1972 and 1982, in which the victims were drugged, strangled, beaten or burned.

He was dubbed The Serpent or the Bikini Killer for his knack for deceptive disguises, ability to escape prison and tendency to target young women. It later became the title for a hit BBC and Netflix series about the killer, which was released in 2021.

Prior to his two convictions in Kathmandu, Sobhraj had already spent two decades in jail in India for poisoning a busload of French tourists.

During that time he briefly managed to escape from prison by drugging the prison guards. He later claimed the escape was a ploy to get his sentence extended and avoid extradition to Thailand where he was wanted for five more murders.

Thai authorities had issued a warrant for him in the mid-1970s on charges of drugging and killing six women, some who were found dead on a beach near the resort town of Pattaya.

Following his release from India in 1997, Sobhraj returned to France where he lived in Paris and gave paid interviews to journalists.

But he returned to Nepal, and was arrested for Bronzich's murder in 2003 after being spotted by a reporter in a casino in Kathmandu.