The Alternative for Germany (AfD) party and other extremists have seized on the brutal killing of 14-year-old Susanna Maria Feldman in their campaign against Chancellor Angela Merkel's asylum policy.

The accused, rejected asylum seeker Ali Bashar, 22, was convicted of the killing and given life in prison.

The court in Wiesbaden, the city where the murder took place in May last year, also found the crime to be of exceptional severity, meaning that Bashar is unlikely to be granted parole after 15 years.