The son of Norway's Crown Princess has pleaded not guilty to four counts of rape at the start of his high profile trial in Oslo.

Marius Borg Høiby, who is the stepson of Norway's future king, is facing 38 charges including four counts of rape as well as sexual assault, drug and abuse charges.  

It comes at a difficult time for Norway's royal family - his mother, Crown Princess Mette-Marit is facing a scandal over her links to the late convicted sex offender Jeffrey Epstein.

• Guest: Ole-Jørgen Schulsrud-Hansen, historian and royal correspondent for Norway's TV2
• Producer: Pip Cook