BERLIN (AFP) - A German couple received lengthy jail sentences Friday (Aug 4) for brutally raping and killing a Chinese student in eastern Germany, in a shocking crime that caused outrage in both countries.

The court in the city of Dessau found that the 21-year-old defendants, named only as Sebastian F. and Xenia I., lured the 25-year-old architecture student to an empty apartment in May last year, DPA news agency reported. They submitted their victim to a horrific ordeal that led to her death.

Presiding judge Uda Schmidt called the case an "incomprehensible crime", handing down a 15-year sentence to Sebastian F. and a juvenile sentence of five years and six months to his partner at the time, who is the mother of three children.

The two defendants, who sat impassively as the verdict was read out, were also ordered to pay a total of 60,000 euros (US$71,300) for the pain and suffering of the victim's parents, who were co-plaintiffs in the case.

Schmidt said the pair's sole motive had been to fulfil a sadistic sexual fantasy.

After trapping her in the flat, the pair repeatedly sexually assaulted the woman, leaving her with such severe injuries that they assumed she would die, the court found.

When the couple returned hours later and found the victim, identified in media reports as Li Yangjie, still alive, they carried the severely injured woman away and abandoned her in underbrush.

After friends in Germany and China alerted the authorities that she was missing, police organised a search for the woman, who was from the eastern province of Henan. Her corpse was found two days later.

An autopsy found she had suffered blows to the head, torso and extremities.

After news of the murder spread, hundreds of Chinese students and local residents held a rally in Li's memory to demand justice.

The couple was arrested two weeks after the crime and went on trial last November.

Xenia I. had admitted in testimony that she had lured the young woman, who was jogging in town, to the empty flat under false pretences and was present while Sebastian F. raped her.

But she denied taking part in the abuse that led to the student's death.

Beyond the shock at the brutality of the crime, the case also caused controversy in Germany and China because the mother and stepfather of Sebastian F. are both police officers.

Sebastian F. is also accused of at least one further rape committed in the summer of 2013 in Dessau which only came to light in the course of the investigation.

Dessau, 130 kilometres (80 miles) southwest of Berlin, is closely associated with the Bauhaus movement and draws architecture and design students from around the world.