A year and a half after Marius Borg Høiby was arrested by police over a violent episode at a woman's flat's in Oslo, the son of Norway's crown princess is going on trial in the biggest case to come to court here for years.

The seven-week trial opens at Oslo district court on Tuesday against a backdrop of almost daily revelations surrounding him and his mother, Crown Princess Mette-Marit.

On the eve of the trial, it emerged that the 29-year-old had been detained again, in circumstances not unlike his initial arrest, on suspicion of assault, making threats with a knife, and violating a restraining order.

As police have placed him on remand for four weeks, he begins the trial in custody. His defence team intends to appeal against this decision.

The crown princess is facing increasing criticism after it emerged that she was cited in hundreds of emails showing extensive contacts with the late sex offender Jeffrey Epstein. She has admitted showing poor judgement, but the fallout has already begun, with one organization dropping her as patron for its annual prize.

Heavy court restrictions have been imposed on the trial, with a ban on any pictures of Marius Borg Høiby inside or outside court and any detail that might identify the four women who he is alleged to have raped.

The royal family will not attend any of the proceedings in Courtroom 250 at Oslo district court, where the trial has attracted enormous interest throughout Norway and beyond. Commentators do not see that as surprising, with King Harald V and Queen Sonja heading to the Winter Olympics in Italy later this week, but it adds to a sense of isolation surrounding Crown Prince Haakon's stepson.

Marius Borg Høiby was born four years before Mette-Marit married the crown prince, and although he is seen as a close member of the family, he is not part of the royal family itself and not a public figure.

His mother suffers from a serious lung condition and has difficulty breathing. However, it is not her health that has become the talk of Norway in recent days, rather her name cited in more than 900 emails published by the US Department of Justice earlier this week.

The correspondence suggests a future queen of Norway exchanging messages while knowing she was talking to a registered sex offender who had previously served time in jail. It has also emerged she spent four days at his home in Florida during his absence.

The Sex and Society foundation has announced it no longer wants Mette-Marit to act as high patron for its annual Shameless Prize, declaring that the information revealed is incompatible with its values.

Prime Minister Jonas Gahr Støre has urged Mette-Marit to provide clarity on the extent of her contacts with Epstein. This tumultuous situation is expected to haunt the crown princess indefinitely, as public sentiment turns against her.

As the trial commences, Marius Borg Høiby faces an array of 38 charges, including serious allegations stemming from incidents that date as far back as 2018. If found guilty, he could face a significant prison sentence.