Madrid, Spain ? Former Argentine President Isabel Peron was briefly detained Friday in Madrid as part of investigations into the South American country’s past human rights abuses, police said.

She appeared at Spain’s National Court, which released her conditionally three hours after her arrest, pending an extradition request from Argentina. The court said Argentina has 40 days to file the request and ordered Peron to appear at a police station every 15 days.

As she walked to a car awaiting her outside the court, a group of protesters shouted at her. She did not speak to reporters.

Police acted on an international arrest warrant from an Argentine investigative judge who said he had questions about Peron’s chaotic 20-month rule, a time when shadowy right-wing violence destabilized Argentina. The third wife of three-time president Juan Domingo Peron was ousted in the March 1976 coup that ushered in a seven-year dictatorship that waged a “dirty war” against its opponents.

Peron, 75, has lived in exile in Spain since 1981.

Her arrest marked the expansion of Argentina’s human rights investigations beyond dictatorship-era crimes to the death squads that terrorized the nation before the 1976 coup.

Peron was taken into custody at her villa in the wealthy northern Madrid neighborhood of Villanueva de la Canada.

She was wanted for questioning about decrees she approved in her brief presidential tenure, calling on armed forces to crack down on “subversive elements.” She was also wanted for questioning in connection with the disappearance of leftist Hector Aldo Fagetti Gallego one month before the coup.