PARIS/SANTIAGO (Reuters) - A French court on Wednesday refused an appeal by Chile to extradite a longtime fugitive leftist guerilla who had escaped prison after being convicted for killing an ally of ex-dictator Augusto Pinochet, spurring an immediate rebuke from Chile.

The French court’s resolution was seen by many in Chile as an affront to the South American nation’s democracy and justice system.

“This decision is incomprehensible,” Chile’s foreign minister, Roberto Ampuero, told reporters. “It is not in line with the principles and standards of international law.”

France granted Ricardo Palma Salamanca asylum in November 2018, more than two decades after Chilean authorities imprisoned him for the 1991 murder of Senator Jaime Guzman.

Center-right President Sebastian Pinera sent a personal letter to French President Emmanuel Macron asking him to overturn the decision. The country also filed an appeal seeking Palma Salamanca’s return to Chile.

“The Paris Court of Appeal handed down a ruling that was not favorable to Chile’s request of extradition,” a spokesman for the court told Reuters on Wednesday.

Palma Salamanca, who faces two life sentences in Chile, famously escaped from a Santiago maximum security prison in a metal basket dangling from a helicopter in 1996, humiliating Chile’s nascent democratic government and stunning the world.

After that, the Chilean national changed his name and hid among foreign residents in the colonial city of San Miguel de Allende, Mexico, before his capture in Paris in February 2018.

The leftist rebel was convicted of killing Pinochet-ally Guzman and thrown in jail shortly after the ex-dictator stepped down following a popular plebiscite. Pinochet remained head of the armed forces, however, prompting questions about whether Palma Salamanca had received a fair trial.

Palma Salamanca’s lawyers have argued that he only confessed to killing Guzman under torture.

Chilean political leaders of all stripes have nonetheless called for his return.

Chile and France do not have an extradition treaty and French law stipulates that no extradition can take place “when the crime has a political aspect or the request is made for political purposes.”