A trial that some have dubbed the “Romanian Nuremberg” opens on Wednesday in Bucharest, with the head of a brutal Communist-era labour camp charged with crimes against humanity.

Alexandru Visinescu, 88, is accused of running an “extermination regime” at the notorious Ramnicu Sarat prison in the east of the country, which he headed from 1956 to 1963.

“In his role as commandant, the accused … submitted the political detainees to conditions designed to destroy them physically, by depriving them of medical care, food and heating and inflicting abuse on them,” the indictment reads.

At least 14 inmates died during his tenure. Many more were left permanently traumatised or disfigured from the camp dubbed “the prison of silence” because detainees were held in solitary confinement and not allowed visitors.

Valentin Cristea, 84, only surviving detainee of Ramnicu Sarat prison during the time of Alexandru Visinescu’s command. Photograph: DANIEL MIHAILESCU/AFP/Getty Images

Valentin Cristea, the only living survivor of the camp, remembers “the cold, the isolation, the hunger”.

Now 84, the former engineer was convicted in 1956 of “divulging state secrets” to an aunt who was a member of the anti-Communist resistance. He spent seven years at the camp.

“It was against the rules to approach the walls in case we used morse code to talk to each other,” he told AFP at his home in Campina, north of Bucharest. He said prisoners were also banned from sitting on their beds, except at night time, and even looking out of the window.

The widow of another detainee, General Ion Eremia who died in 2003, recalled the treatment of her husband who was sentenced to 14 years in prison and 25 years’ forced labour for writing a satirical novel about Stalin.

“One day in winter, he was forced to stand for several hours with bare feet in a bucket of ice water,” said Nicoleta Eremia.

“This burly man weighed no more than 30 kilos (70 pounds) and could barely walk when he came out of prison.”

Activists hope Visinescu’s trial will be the first of many, with prosecutors looking at 35 other former Communist officials.

“This trial is particularly important, because for the first time an instrument of communist terror will face justice,” said Radu Preda, head of the Institute for the Investigation of Communist Crimes and Memory of the Romanian Exile (IICCMRE).

“Without hyperbole, this amounts to a Romanian Nuremberg,” he said, referring to the famous trials of Nazi leaders after the second world war.

Visinescu has said he is innocent and was only obeying orders. If convicted, he faces life in prison.

The trial comes a quarter century after the downfall of dictator Nicolae Ceausescu, who was executed, along with his wife Elena, on Christmas Day 1989, following an impromptu trial in which they were convicted of genocide.

Most Communist-era officials went unpunished. Although a few top leaders were also convicted of genocide, many of the charges were later reduced and they were released on health grounds.

But pressure has mounted for a true accounting of the regime’s crimes, which included the imprisonment of more than 600,000 dissidents from the late 1940s onward.

A first complaint by the IICCMRE in 2006 against 210 former prison guards was rejected by prosecutors.

But in 2013, new prosecutors indicated they were finally prepared to listen, accepting a fresh demand for Visinescu and others to go on trial.

Public response to the trial has been muted, amid nostalgia for the Communist era and disillusionment with the country’s entry into the European Union in 2007.

For many victims, any trials would come too late, since most of the accused are already in their eighties.

But historian Adrian Cioroianu says that what matters is “that these crimes are punished and that the truth is re-established”.

The interior of the prison in Ramnicu Sarat, Romania. Photograph: DANIEL MIHAILESCU/AFP/Getty Images

Preda also believes it is never too late to seek justice. “We must personalise evil, otherwise it risks becoming an abstraction,” he said.

Romania is an exception in central Europe, where Communist-era leaders have largely escaped punishment.

Former Polish strongman Wojciech Jaruzelski enjoyed a quiet retirement after the end of the cold war, while Bulgarian dictator Todov Jivkov was acquitted after a trial.

“This trial is necessary so that people discover the horrors which marked this epoch,” said Steluta Coposu, sister of Corneliu Coposu, a former detainee and member of the anti-Communist resistance, who died in 1995.

Visinescu’s trial is expected to last several months, possibly even years.

Health concerns could prove an obstacle. His lawyer, Dan Petre, told AFP he was concerned by his client’s “precarious physical and mental state”, a point that sources close to the case say could be used to argue for an acquittal.