Although 64-year-old Sobhraj, a French citizen, is being held for violating immigration laws, the Nepal Police have charged him with the murder of two backpackers, a Canadian and an American, in 1975.
He has been accused of luring young women and killing many of them, thereby earning the sobriquets 'The Serpent' and the 'Bikini Killer'.
Sobhraj is also accused of killing over 20 young western backpackers across Asia, usually by drugging their food or drink, while on a criminal spree in the 1970s and 1980s.
Thailand issued a warrant for his arrest on charges of drugging and killing six girls, all wearing bikinis, at the beach resort town of Pattaya in 1975. He was jailed in India before he could stand trial on those charges.
A master of disguise and escape, Sobhraj served more than two decades in and out of Indian jails on a string of charges including murder and robbery before returning to France in 1997.
Born to an Indian father and a Vietnamese mother, his criminal exploits across Asia have been the subject of a film, two books and countless newspaper and magazine articles.