Romanian prosecutors have charged a communist-era prison commander, Alexander Visinescu, with genocide.
It is the first such charge in Romania since the 1989 revolution which led to the execution of former communist leader Nicolae Ceausescu.
Mr Visinescu, 88, could face life in prison if found guilty. He was head of the Ramnicu Sarat prison in 1956-1963.
Prosecutors say political prisoners there suffered beatings, hunger, cold and lack of medical treatment.
Mr Visinescu lives in Bucharest and went to the prosecutor-general's office on Tuesday, where he was indicted.
He told prosecutors he was only following orders.
Former political prisoners, quoted by the Romanian news agency Agerpres, described him as "a very cruel man".
The Romanian Institute for the Investigation of Communist Crimes (IICCMER) listed him among 35 former communist officials whom it accuses of human rights abuses. It asked prosecutors to launch the case against Mr Visinescu "for first degree murder".
The institute said the prison regime at Ramnicu Sarat "can be considered as one of extermination, given the inhumane imprisonment conditions, which eventually led to the death of several political prisoners".
About 500,000 Romanians, including priests, teachers, doctors and peasants, were jailed as political prisoners in the 1950s as the communist authorities imposed a totalitarian system. In harsh prison conditions about one-fifth of those inmates died, historians say.