Norwegian Princess Martha Louise is set to marry American self-proclaimed shaman Durek Verrett on Saturday, a union of two alternative therapy devotees that has raised eyebrows in Norway.

Martha Louise, a 52-year-old divorcee, claims to be a clairvoyant who can speak with angels, a gift she has shared -- and profited from -- in books and courses.

Verrett, 49 and from California, calls himself a "sixth-generation shaman" and sells pricey gold medallions that he says save lives.

"I'm very spiritual, it's just so nice to be with a person who embraces it," Martha Louise said on Instagram after the couple announced their engagement in June 2022.

The pair will tie the knot Saturday at 1:00 pm (1100 GMT) at a hotel in the hills of Geiranger, a picturesque village on the shores of a fjord on Norway's west coast.

Festivities kicked off Thursday with a meet-and-greet party for the more than 350 guests, including Sweden's Crown Princess Victoria and her husband Prince Daniel.

On Friday, guests were treated to a boat trip in the fjord and a pre-wedding salsa party in the evening.

According to Verrett, the nuptials are actually a renewal of the couple's vows.

The spiritual guide, who counts Hollywood celebrities Gwyneth Paltrow and Antonio Banderas among his followers, claims he was a pharaoh in a previous life and Martha Louise was his wife.

The couple's eccentricity has ruffled feathers in no-nonsense Norway, as has their disregard for science and their use of their royal ties for commercial gain.

To avoid confusion over her role, Martha Louise relinquished her royal duties in November 2022. She kept her title but agreed not to use it in her commercial endeavours.

She has however violated the agreement several times since then, most recently when she and Verrett released a "wedding gin" for sale in Norway that bore her princess title on the label.

"Seeing as the agreement has not been respected, it's time to take away Martha Louise's princess title before King Harald sees his life's work destroyed even further," historian and royal expert Trond Noren Isaksen wrote in an op-ed in July.

The couple has also angered Norwegian media by signing deals with Hello! magazine and Netflix for exclusive coverage of the wedding.

- Falling popularity -

Martha Louise has three daughters from her first marriage to Norwegian author Ari Behn, who killed himself three years after their 2016 divorce.

She is fourth in line to the Norwegian throne; her younger brother Crown Prince Haakon is due one day to succeed King Harald.

Norway's royal family has been largely spared from scandal -- until recently.

Martha Louise and Verrett have contributed to an erosion of public support for the monarchy, from 81 percent in 2017 to 68 percent, a poll by public broadcaster NRK showed this week.

A recent scandal involving the 27-year-old son of Crown Princess Mette-Marit -- from a relationship prior to her marriage to Crown Prince Haakon -- has also contributed.

Earlier this month, Marius Borg Hoiby admitted to a cocaine- and alcohol-fuelled assault on his girlfriend, and two ex-girlfriends have since come forward with similar claims.

Four in 10 Norwegians said their view of the royal family had grown more negative in the past year, with many citing Martha Louise, Verrett or Hoiby as the reason, the poll showed.

- Witch hunts and quacks -

Martha Louise has accused the media of pursuing a witch hunt against her.

But it is Verrett who has received the most criticism, labelled a "charlatan and a quack" in the press.

In one of his books, he suggested that cancer was a choice, and recommended exercises to remove "imprints" from women's vaginas left by previous sexual partners.

On his website, he sells a $222 "Spirit Optimizer" medallion which he says helped him overcome Covid.

While Verrett has acknowledged his beliefs may be unsettling for some, he claims he is a victim of racism -- echoing fellow Meghan Markle's complaints after she joined Britain's royal family. She is biracial, with an African-American mother.

"White people write all this hate and death threats to us... because... they don't want to see a black man in the royal family," he said on Instagram in June 2022.

Meanwhile, 87-year-old King Harald -- who fought for years to be allowed to marry Queen Sonja, a commoner -- has said little about his future son-in-law, referring only to a "culture clash".

He has described him as "a great guy and very funny".

"We've agreed to disagree" on some things, the king said in November 2022.