Confessed French serial killer Charles Sobhraj was freed from prison in Nepal on Friday after serving most of his sentence for the murders of American and Canadian backpackers.

Sobhraj was driven out of Central Jail in Kathmandu in a heavily guarded police convoy to the Department of Immigration, where he will wait for his travel documents to be prepared.

The country’s Supreme Court had ordered that Sobhraj, who was sentenced to life in prison in Nepal, be released because of poor health, good behavior and having already served most of his sentence. Life sentences in Nepal are 20 years.

The order also said he had to leave the country within 15 days.

Sobhraj’s attorney Gopal Siwakoti Chitan told reporters that the request for the travel documents must be made by the immigration department to the French embassy in Nepal, which could take some time. Offices are closed over the weekend for the Christmas holiday.

The court document said he had already served more than 75% of his sentence, making him eligible for release, and he has heart disease.

The Frenchman has in the past admitted killing several Western tourists and he is believed to have killed at least 20 people in Afghanistan, India, Thailand, Turkey, Nepal, Iran and Hong Kong during the 1970s. However, his 2004 conviction in Nepal was the first time he was found guilty in court.

Sobhraj was held for two decades in New Delhi’s maximum-security Tihar prison on suspicion of theft but was deported without charge to France in 1997. He resurfaced in September 2003 in Kathmandu.

His nickname, The Serpent, stems from his reputation as a disguise and escape artist.