The appeal trial of Marius Borg Høiby, the eldest son of Norwegian Queen Mette-Marit, is set to begin on February 9 next year, the Oslo court said on Thursday.

Høiby was sentenced to four years in prison in June for numerous offences – including two rapes under Norwegian law and domestic violence against a former girlfriend.

He appealed against the verdict, and the court recently decided to allow the appeal.

“Provisionally, 16 days have been set aside for the appeal proceedings,” the court said. The final day of proceedings is expected on March 5.

Høiby, 29, has been in pre-trial detention since early February, though he has been serving that time under electronic tagging at Skaugum, the Norwegian royal family’s estate.

He has also been granted several periods of leave – including to say goodbye to his terminally ill step-grandfather, king Harald V, and to attend his funeral last week.

The time spent in pre-trial detention is to be deducted from his prison sentence.