The 28-year-old, who does not have a royal title or official duties, had been under investigation since his arrest on 4 August 2024 on suspicion of assault.
In a statement, external, Oslo Police District said they carried out a “thorough investigation”, with a “large number of witness interviews, several searches and a review of extensive digital material”.
Høiby was questioned several times during the autumn of 2024 and spring of 2025 and “cooperated with the police”, the statement said.
Amongst the offences police said Høiby was suspected of were four counts of sexually offensive behaviour, one count of abuse in a close relationship and two counts of bodily harm.
Police confirmed that some cases involving sexual offences had been dismissed due to “statute of limitations and evidentiary reasons”.
“I cannot go into further detail about the number of victims in the case beyond confirming that it is a double-digit number,” Mr Kruszewski said.
The Royal House of Norway noted in a statement that the case was proceeding through the legal system and had nothing further to add.