Marius Borg Hoiby has no royal title or duties, but as the stepson of the heir to the throne, his arrest has cast a cloud over Norway’s popular royal family.

Police in Norway have arrested the 27-year-old son of Crown Princess Mette-Marit on suspicion of rape, saying the alleged victim was "unable to resist the act."

The 27-year-old son of Norway's crown princess was arrested on Monday on suspicion of rape, one of many allegations against Marius Borg Hoiby.