A German citizen was handed a 10-year sentence for causing the death of a prisoner.

The citizen was sentenced by a Dusseldorf court on Friday after being found guilty of torturing the prisoner to death in a prison operated in Syria by the Islamic State extremist group.

The man, named only as Nils D under German privacy laws and aged 31, was also convicted of a war crime.

He had been convicted by the same court of membership of the Islamic State terrorist group in 2016 and sentenced to four-and-a-half years.

The prosecution called for a life sentence for the killing, charging that there were no extenuating circumstances.

The defence pleaded for acquittal.

Nils D was a member of the so-called “Lohberg Brigade’’ of Islamist extremists from Dinslaken-Lohberg, a former coalmining region to the north of Dusseldorf, who went out to Syria to join Islamic State.

Following his conviction, former prisoners reported to the German authorities that he had tortured prisoners in the prison in Manbij, a city in Aleppo Governorate near Syria’s border with Turkey.