Pictures taken by “Caesar”, a Syrian military police photographer who defected and secretly documented regime abuses were also used as evidence against Raslan.

They included disturbing images of the bodies of 110 dead inmates removed from al-Khatib prison.

A German forensic expert testified that 55 showed evidence of blunt force injuries, while others appeared to have starved to death.

“More than 10 years after the violations were committed in Syria, the German court’s verdict is a long-awaited beacon of hope that justice can and will in the end prevail,” said Balkees Jarrah, associate international justice director at Human Rights Watch. 

“Other countries should follow Germany’s lead, and actively bolster efforts to prosecute serious crimes in Syria.”

The conviction of Raslan is the latest in a series of decisions by the German courts to hold perpetrators to account over the crimes in Syria and Iraq in recent months.

Eyad al-Gharib, a junior intelligence officer who served under Raslan, was convicted of aiding and abetting crimes against humanity and sentenced to four and a half years as part of the same trial last year.

Taha al-Jumailly, a former member of Islamic State, was found guilty of genocide against the Yazidi people and sentenced to life in prison last November for crimes including the murder of a five-year-old girl he chained in the sun to die of thirst.

Al-Jumailly’s German former wife, Jennifer Wenisch, was found guilty of aiding and abetting the girl’s murder and sentenced to ten years in prison.