Lawyers for the former police officer had appealed to the European Court of Human Rights to take up his case, but failed. Sandoval is wanted over an alleged kidnapping and a slew of other disappearances.
France said it will extradite Mario Sandoval to Buenos Aires on Sunday evening to face trial over the torture and disappearance of a student during Argentina's 1976-83 military dictatorship.
The former police officer was arrested Wednesday in Paris, after French authorities gave the final go-ahead for his extradition, ending eight years of legal tussels.
He will sent back on board an Air France flight from Paris to Buenos Aires.
Torture suspect 'faced torture'
The 66-year-old is wanted over the alleged kidnapping in 1976 of Hernan Abriata, an architecture student whose body has never been found, as well as a slew of other disappearances.
Sandoval's lawyers had argued that he would not be able to get a fair trial in Argentina and faced torture or poor detention conditions there.
But their appeals to the European Court of Human Rights to take up his case failed.
Despite being a French citizen. he can be extradited because the alleged crimes took place before his citizenship was granted in 1997. He had been living in France since 1985.
Prosecutors in Argentina suspect Sandoval was involved in at least 500 cases of kidnappings, torture, murder and other human rights violations during the country's dictatorship.
Argentina's National Commission on the Disappearance of Persons has confirmed that nearly 9,000 forced disappearances during the military dictatorship, although it noted that the number could much higher.
The 'dirty war'
Many Argentines welcomed a military intervention in 1976. For many years before, extremist left-wing guerillas — Montoneros — had terrorized the country. After a coup led by Jorge Rafael Videla, many hoped for calm and peace — until the dictator banned political parties and shut down parliament. By then, it was too late to turn back. The 'dirty war' of the dictatorship had already begun against its own people.
When the dictatorship finally ended in 1981, Videla was sentenced to life in prison. In 1990, then-president Carlos Menem pardoned Videla, but the country's Supreme Court annulled the amnesty in 2010.
Read more: Former officials convicted in Argentina's 'dirty war' trial
Videla died in 2013 in a Buenos Aires prison at the age of 87. During his rule, between 1975 and 1981, an estimated 30,000 people disappeared or were killed, including dissidents, journalists and students.
kw/rc (AFP, Reuters)