Norwegian police said Tuesday that the 27-year-old son of Norwegian Crown Princess Mette-Marit had been arrested on suspicion of rape.
Police said in a statement that Marius Borg Hoiby, who was born from a relationship prior to Mette-Marit's 2001 marriage to Crown Prince Haakon, had been arrested Monday evening.
He was suspected of violating the criminal code "which concerns sexual intercourse with someone who is unconscious or for other reasons unable to resist the act", the statement said.
"What police can say about the rape is that it concerns a sexual act without intercourse. The victim is said to have been unable to resist the act," police said.
Borg Hoiby was detained on August 4 following a night-time row at a woman's apartment in Oslo and accused of causing bodily harm to the resident, with whom he was having a relationship, police said.
Norwegian media reports said police found a knife stuck into one of the walls of the woman's bedroom at the time.
He was arrested again in September for violating a restraining order.
According to police, when he was arrested on Monday he was in a car with the alleged victim from the August incident.
On Tuesday, police also said the suspicions relating to the August incident now included domestic abuse.
Police said they had yet to decide whether he would be remanded in custody.
Hoiby was born in 1997 from a relationship prior to Mette-Marit's 2001 marriage to Crown Prince Haakon, the heir apparent to the Norwegian throne.
He and his step-siblings -- Princess Ingrid Alexandra, 20 and Prince Sverre Magnus, 18 -- were raised together by Mette-Marit and Haakon.
Unlike them, he has no official public role.