One of the most notorious figures from the regime of former military ruler of Chile, General Augusto Pinochet, has died in prison, officials have said.
Romo worked at the notorious Villa Grimaldi detention centre
Osvaldo Romo, who was serving 15 years in jail for killing three dissidents during Gen Pinochet's rule, died of heart and respiratory problems.
Known as "El Guaton" (The Fat One), he was awaiting trial for human rights abuses committed between 1973 and 1990.
Romo fled to Brazil afterwards, but was eventually extradited back to Chile.
A former officer in the feared Dina secret police force, Romo was accused by his victims of being a sadistic torturer.
He worked at the notorious Villa Grimaldi detention centre in the capital, Santiago, where Chile's current president, Michelle Bachelet, was briefly held in the 1970s.
Romo once boasted about his actions in a TV interview he gave in prison.
He said he had told the Dina commander, Gen Manuel Contreras, that it was a mistake not to kill some jailed dissidents.
He said that he told Gen Contreras: "Let's not leave any of these kids alive, my general."
Romo also infiltrated leftist groups prior to the 1973 military coup in which Gen Pinochet overthrew Marxist President Salvador Allende.
More than 3,000 people were killed or "disappeared" during Gen Pinochet's 17-year rule.