(CNN) -- Former Argentine dictator Gen. Reynaldo Bignone was sentenced Thursday to 15 years in prison for crimes against humanity at a clandestine detention center during his rule. He was already serving a 25-year sentence from a previous trial.
He ruled Argentina from June 1982 until the nation's return to democracy in December 1983.
Argentina's 2nd Oral Federal Court handed down the ruling.
The punishment stems from an investigation into a clandestine detention facility hidden inside a hospital during the country's military dictatorship.
Under his command, at least 22 people were kidnapped and taken to the center, known as the "Chalet at the Posadas Hospital," according to evidence in the case. Five of those were tortured during their detention, according to Argentina's judicial information center.
Bignone, was previously sentenced in April 2010 to 25 years in prison for kidnapping and torturing 56 people.
Up to 30,000 students, labor leaders, intellectuals and leftists who ran afoul of the dictatorship because of their political views disappeared or were held in secret jails and torture centers during the nation's eight-year "dirty war."