Mario Sandoval, who moved to France after the fall of Argentina’s seven-year military dictatorship and obtained French citizenship in 1997, is accused by Argentine prosecutors of more than 600 human rights violations including torture.

Thursday’s ruling by the Cour de Cassation ends a five-year legal tussle. A decree permitting Sandoval’s extradition needs now to be signed by the French government.

“It is time for Mario Sandoval to face Argentine justice,” said Sophie Thonon-Wesfreid, a lawyer representing Argentina.

Sandoval’s attorney said the ruling was a “disappointment”.

A former federal police officer, Sandoval is accused of committing crimes at a secret prison where he was a specialist in fighting “subversive elements”. He denies the charges.

As many as 30,000 Argentines were murdered during the military dictatorship’s so-called dirty war against suspected leftists and political dissidents, according to human rights groups.