The police filed the case against Sobhraj, 70, in the Bhaktapur District Court after recording his statements in connection with the murder of Laurent Carrere.
"We have succeeded in recording his statements regarding the murder of a Canadian male tourist after making hard efforts and his statements would be significant enough to convict him in the murder case," said Deputy Superintendent of Police Ramesh Thapa.
"Now we will submit the statement of Sobhraj along with other evidences to the Bhaktapur District Court soon," Thapa said.
Sobhraj is serving a life term in central jail of Kathmandu since 2003 for the murder of US woman Connie Joe Bronzich in 1975,
More From This Section
Of the total 20 year term, Sobhraj has already spent fifty per cent time in the prison.
Sobhraj had chances of an early release due to his old age, but the new case being filed against him has lessened his hopes, legal experts said.
Sobhraj had earlier refused to speak to the police twice when they approached him.
Five years ago, Sobhraj made headlines after he reportedly married a 22-year-old Nepali girl Nihita, daughter of his lawyer Shakuntala, in the jail.
Sobhraj, who is born to an Indian father and Vietnamese mother, is believed to have killed 15 to 20 people in 1970s.
After several escapes from prison, he was dubbed "the Serpent".
Sobhraj escaped Tihar Jail in 1986 after drugging security guards, whom he had served sweets in the pretext of celebrating his birthday.
After his unsuccessful attempts to escape from jail in Nepal, Sobhraj has been put under tight security in the prison.