Høiby had requested to be released from custody pending sentencing, which will be on Monday. He said this was because his mother, Norway's Crown Princess Mette-Marit, is seriously ill with pulmonary fibrosis and has been placed on a waiting list for a lung transplant.
But his request was denied, citing the prosecutor's appeal of the district court's decision to release Høiby.
"The Supreme Administrative Court has concluded that there is still a strong likelihood that Høiby will commit new criminal acts if he is released," the decision states, among other things, according to NRK.
Høiby's lawyers announced that they are disappointed, but that the rejection would not be appealed further.
The 29-year-old so-called "bonus prince" is suspected of several rapes, among other offences. He is the Crown Princess's son from a previous relationship.
"I want to go out and be there for my mother," Høiby said in the district court on Monday.
