His mother has not commented on the trial but Crown Prince Haakon told reporters in Oslo there was a lot going on in his family and the most important thing in the past few days “has been to take care of the flock”.
“We support Marius in the situation he is in. We look after the other children as well… They also need to be cared for, and I have to make sure to take care of the crown princess,” he said.
Mette-Marit is also extremely unwell with pulmonary fibrosis and her doctors are preparing to put her on a list for a lung transplant.
Giving evidence in court on Wednesday, her son initially struggled to compose himself, holding back tears as he complained of being “hassled” by the press since he was three years old.
If found guilty by the three judges at Oslo district court, he could face a jail term of at least 10 years. Two days before the trial began, he was arrested for a fourth time on Sunday, on suspicion of assault, wielding a knife and violating a restraining order.
His half-sister Princess Ingrid Alexandra, 22, was also critical of the press in a post to almost 800 followers on a private Instagram account this week.
In lengthy comments seen by public broadcaster NRK, Aftenposten and VG website, the princess, who is second in line to the Norwegian throne after her father, said it was important “not to make claims you have no basis for”.
While stressing she was not referring to anything in particular – “not Marius, not mum or dad or Magnus. It’s about personal attacks, it can apply to anyone, but I chose to post this here because I’m going crazy. Enough is enough”.
When approached by the BBC, the palace said it did not wish to comment on the matter.