A Norwegian appeals court has ruled that Marius Borg Høiby must remain behind bars despite his mother, Crown Princess Mette-Marit's deteriorating health condition.
The Borgarting Court of Appeal overturned an earlier decision from Oslo District Court, which had granted the 29-year-old's release on compassionate grounds on Monday.
Judges determined there remains a substantial probability that Mr Høiby would commit further offences if freed from custody.
The ruling came after prosecutors immediately challenged Monday's release order, keeping Mr Høiby detained while the appeal was considered.
A court sketch depicts Marius Borg Hoiby, son of Norwegian Crown Princess Mette-Marit, during the third day of a trial in Oslo at the District Court on February 5, 2026
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His legal team expressed profound frustration at the outcome. "We are very, very disappointed and find the decision almost incomprehensible," defence lawyer Ellen Holager Andenæs told Norwegian broadcaster NRK.
Despite their dismay, the defence confirmed they would not pursue a further appeal to Norway's Supreme Court.
Mr Høiby stands accused of 40 criminal offences, with the most serious being four counts of rape against women who were allegedly asleep or incapacitated following consensual sexual activity.
One charge involves intercourse, while the remaining three relate to alleged sexual assault.
Marius Borg Hoiby and Princess Mette-Marit pictured in 2016
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The prosecution has requested a prison term of seven years and seven months, while his defence team is seeking full acquittal on the rape allegations.
He denies the four counts of rape but has admitted to some lesser offences, including drug possession and traffic violations.
The judges must also consider accusations of violence, threats and abusive conduct within relationships, all of which Mr Høiby denies.
His trial ran from February 3 to March 19, and the verdict is scheduled for Monday, June 15.
Crown Princess Mette-Marit, 52, suffers from pulmonary fibrosis, an incurable condition that creates scar tissue in the lungs and impairs oxygen absorption.
A court sketch depicts Marius Borg Hoiby with his defence lawyers Ellen Holager Andenaes and Petar Sekulic
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Her health has declined markedly over recent months, prompting doctors to place her on the transplant waiting list last Friday.
Lung specialist Dr Are Holm of Oslo University Hospital explained that patients are typically added to such lists when they are believed to have approximately one year left to live.
The crown princess now relies on an oxygen machine daily and has withdrawn from official duties while awaiting surgery.
Mr Høiby, who has been detained since February 1, made an emotional plea to the lower court last week.
"Sitting in there while Mum is so ill is unbearable," he told judges, adding that being unable to support her was extremely difficult.
State Attorney and Prosecutor Sturla Henriksboe and police prosecutor Andreas Kruszewski address the District Court in Oslo
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The appeals court rejected arguments that Mette-Marit's illness would diminish the likelihood of her son reoffending.
Judges stated the matter was "not a question of will, but a question of ability, life patterns and risk factors."
The court noted that Mr Høiby had previously breached restraining orders despite understanding the consequences, and had continued offending despite the burden placed on his family and the royal household.
In its ruling, the court observed it could not identify how Mr Høiby's circumstances in detention differed from those of other prisoners with seriously ill parents or close relatives.
The scandal has damaged the Norwegian monarchy's reputation, compounding difficulties following revelations earlier this year about Mette-Marit's friendship and correspondence with convicted American sex offender Jeffrey Epstein between 2011 and 2014. Mette Marit has previously apologised for her contact with Epstein and for not knowing sooner "what kind of person he was".