Horrific images have been circulating online since the liberation of Saydnaya Prison in Syria, five floors of which were hidden underground.

The images show gaunt, emaciated people, some standing in packed, overcrowded cells. Many prisoners had to be carried out of the building. The liberators also filmed a room where people were huddled in the semidarkness, screaming. Numerous bodies were found with signs of having been tortured to death. Thousands of prisoners were being held in the complex on the day it was liberated, according to media reports.

As many as 15,000 people were extrajudicially executed in the prison between September 2011 and December 2015 alone, according to the human rights organization Amnesty International.

Some people on social media see a direct link to the Nazis, in particular, Alois Brunner, a commanding officer in the Nazi paramilitary SS who fled to Syria in 1954. Brunner was a close associate of Adolf Eichmann, who, as one of the architects of the so-called "Final Solution," was partly responsible for the persecution, expulsion, deportation and murder of millions of Jews.

Former Nazis 'valued for their practical experience'

Brunner was not the only former SS or Wehrmacht member in Syria, as Noura Chalati from the Leibniz Zentrum Moderner Orient in Berlin research institution explained.

"Many of them were employed directly by the Syrian general staff on one-year contracts, advising the army and the military intelligence service," she said.

Documents show that the general staff was particularly interested in these people because, at the time, they were stateless, from a country that supposedly had no colonial history — and, of course, because of their experience in war, including with methods of mass extermination.

"They were valued for their practical experience," said Chalati, whose research focuses on the relationship between the former East German state security service (Stasi) and Syria's secret services.

Brunner, who was sentenced in absentia to death for crimes against humanity in France in 1954, arrived in Syria shortly afterward under a false identity. In his book "Fugitives," about Nazi war criminals who fled abroad, Israeli historian Danny Orbach wrote that Brunner soon got involved in the smuggling of Western arms to Arab countries.

In 1959, the then-head of one of Syria's secret services had Brunner arrested on suspicion of spying and threatened him with life imprisonment, whereupon Brunner revealed his true identity and offered his services to Syrian intelligence.

Over the years that followed, Brunner trained intelligence personnel in counterespionage and interrogation techniques. Many infamous Syrian secret servicemen took part in his training courses, including General Ali Haydar, who led the Syrian special forces for 26 years, Ali Douba, head of military intelligence, and Mustafa Tlass, subsequently defense minister for the Assad regime, who was responsible for brutally suppressing the Muslim Brotherhood-led uprising in Hama in 1982, in which as many as 30,000 people were killed.

Brunner 'knew exactly how to extract and use information'

One of the instruments of torture used until just recently by the Assad regime was known as the "German chair," an instrument which stretched victims until their spine broke. It has often been suggested that the chair was Brunner's invention.

Orbach considers this theory plausible, albeit unproven. He writes that Brunner helped to create gruesome instruments of torture, and the "German chair" may have been one.

Brunner proved useful to Syrian dictator Hafez Assad, who seized power in 1970 and was the father of Bashar Assad. "He knew exactly how to extract and use information, how to manipulate people, what is important for the activities of secret services," wrote Brunner's biographer, Didier Epelbaum. "He knew more than any Syrian officer. As a result, he was involved in restructuring the secret service."

Investigative journalist Hedi Aouidj told the radio station France Inter in 2017 that this knowledge enabled Brunner to maintain his position with the Syrian political elite.

"The deal was protection. In exchange for Nazi know-how. Brunner trained the Nazi secret service, the circle closest to Hafez al-Assad," explained Aouidj, who was able to shed light on Brunner's final years. He said Brunner was ultimately thrown in prison by the Assad regime in 1996, where he remained until his death, thought to have been in 2002.

Assistance from the Stasi

But the Syrian leadership didn't rely solely on fugitive Nazis for help. It also accepted support from the former the state security service of the East Germany — the Stasi.

This made political sense, according to the logic of the Cold War. Although Syria was non-aligned in the 1960s, under the Baath regime, it increasingly aligned itself with Europe's Eastern Bloc.

Noura Chalati said contact was initially established following a request from Syria in 1966. Damascus was interested in everything from weapons technology to the structure and organization of intelligence services and political institutions.

"However, the ministry for state security [Stasi] was very reticent," according to Chalati. As she pointed out, it's difficult to obtain documentary evidence of their collaboration, as the Stasi destroyed all the relevant files when it was dissolved in 1989.

'Worst of both worlds'

In fact, Chalati said it's difficult to prove conclusively that either Nazis or the Stasi directly influenced the Syrian secret services. "The overall picture, though, fits pretty well with what we are currently seeing in Syria," she said. 

Files currently being unearthed show that the Syrian intelligence service was characterized by excessive bureaucracy. "This is a phenomenon we're familiar with from the GDR and the Stasi," said Chalati. "I can't claim that there's a direct, causal connection, but it's a striking phenomenon. Perhaps it's also a characteristic of secret services generally; more research on this is needed."

At the same time, the Syrian secret service was an instrument of suppression and torture by the regime, committing the most serious of human rights violations. This approach, Chalati said, resembles that of the Nazis and the Gestapo more than that of the Stasi.

"Essentially, we are looking at a regime and a secret service complex that combines the worst of both worlds," she said.

This article was originally written in German.