Marius Borg Høiby, son of Norwegian Crown Princess Mette-Marit, in 2022.

An Oslo court has convicted Norwegian Crown Princess Mette-Marit's son of two counts of rape, sentencing him to four years in prison in a high-profile scandal that has rocked the monarchy.

Marius Borg Hoiby, 29, Mette-Marit's son from a relationship prior to her 2001 marriage to Crown Prince Haakon, was accused of 40 charges, from rape to traffic violations, carrying a maximum possible sentence of 16 years in prison.

One of the rapes for which he was convicted took place at the crown prince couple's official residence in 2018.

Hoiby, who is not formally part of the royal household and has no steady job, was acquitted of two other counts of rape, and convicted of repeated domestic abuse against an ex-girlfriend, traffic violations, issuing threats and other offences.