Crown Princess Mette-Marit of Norway has given a much-anticipated interview on her contacts with the late sex offender Jeffrey Epstein, which is due to be broadcast by NRK TV on Friday.

The interview was recorded with Crown Prince Haakon at their residence in Skaugum on Thursday, as her son Marius Borg Høiby's rape trial neared an end at Oslo District Court.

His trial began at the start of February, as his mother faced mounting questions over her links to Epstein which came to light in hundreds of emails.

The crown princess has already issued an apology and admitted to showing poor judgement, but had said she needed time before explaining herself in greater detail.

As the scandals buffeting Mette-Marit's family mounted, Prime Minister Jonas Gahr Støre said at the time he agreed that she had exercised poor judgement. It was seen as a rare public criticism of a royal figure.

Although the crown princess stayed away from the trial, the timing of her interview indicates she and the crown prince were waiting for proceedings to come to an end before going public.

The seven-week trial has been followed very closely by Norwegians, who have seen Høiby grow up alongside the royal family without being a member of it. He was four when his mother married Crown Prince Haakon in 2001.

The 29-year-old faces 40 charges ranging from four counts of rape and serious assault and abuse to drugs and traffic violations. He denies the most serious charges and his defence lawyers told the court on Thursday he should be cleared of rape, and that an 18-month jail term was appropriate for the offences he had admitted to.

Prosecutors earlier asked the three judges to hand down a sentence of seven years and seven months. The judges are expected to give their verdict in June.

The first rape charge, dating back to 2018, took place at his the crown prince and princess's official Skaugum estate outside Oslo. Commentators saw his trial as the biggest scandal Norway's royals had ever had to face.

The weekend before the trial started, hundreds of emails dating from 2011-14 emerged linking the crown princess to Epstein, intensifying public scrutiny and heaping embarrassment on the royal family. They revealed that she had spent four days at Epstein's Palm Beach house in Florida while he was not there and that she was aware of his shady past.

As well as seeing her eldest child on trial in Norway's biggest court spectacle for years, Mette-Marit is suffering from ill health, having contracted the lung disease pulmonary fibrosis. Her condition has deteriorated, according to the royal household.

Two organisations of which Mette-Marit was patron have already ended their collaboration with her while others have asked for an explanation.