An Argentine judge has asked Spain to arrest and extradite 20 former officials accused of abuses during the military rule of General Franco.
They cannot be tried in Spain because of an amnesty law but the officials could be prosecuted in Argentina.
The families of alleged victims asked Argentina for help because it has an extradition treaty with Spain.
In April, Spain's high court refused to extradite to Argentina a former policemen accused of torture.
Judge Maria Servini de Cubria issued the arrest and extradition warrants for two former ministers of General Franco's regime, and 18 other officials, invoking "universal jurisdiction" - a legal doctrine that authorises judges to try serious rights abused committed in other countries.
Using the doctrine, Spain briefly detained Chile's former dictator Augusto Pinochet in 1998.
The two most prominent suspects in Judge Servini's investigation are Rodolfo Martin Villa, 79, who was Franco's interior minister, and Jose Uteri Molina, 86, who was housing minister.
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http://www.bbc.co.uk/news/world-latin-america-29868270