Ten men, mostly Syrian refugees but also including one German national, have been found guilty over the gang rape of a woman outside a nightclub in Freiburg, a southern city of Germany, the BBC reports.

The woman, who was 18 at the time of the attack, was drugged by a group of men in the club, and later subjected to a two hour ordeal in bushes close to the venue.

The rapists claimed she had consented to having sex with at least eight men.

The German Bild reported that the woman had her drink spiked by one of the perpetrators, who then dragged the woman into nearby bushes and raped her. He then returned to the club to call his friends, and the woman was then raped by at least seven other men.

The case caused an uproar in Freiburg, which had already been shocked by the death of Maria Ladenburger, a 19-year-old medical student, who was raped and drowned by an Afghan asylum seeker, and ignited a debate about the open door policy introduced by Angela Merkel towards refugees.

A German regional court yesterday jailed the lead defendant for five and half years while seven of his co-accused received sentences of up to four years. Eight of the men on trial were refugees from Syria, while the other three came from Iraq, Afghanistan and Germany. Two received suspended sentences for failing to assist the woman, while one was acquitted.

Freiburg mayor Martin Horn told the Süddeutsche Zeitung that the gang rape had horrified the city, but he said most people did not wish to use the case to make general assumptions about immigrants.

The BBC noted that “Ms Merkel received both widespread praise and criticism for her “open door” policy. She has since admitted that Germany was ill-prepared for the influx”.