‘The Secrets of Angels’ has taken the country’s bestseller lists by storm since its release two weeks ago. After an initial print run of 11,400, the book’s publishers are already preparing to release a further 4,000 copies.

The princess, who has set up her own alternative medicine business, wrote the book with fellow author Elisabeth Nordeng.

"There are an infinite number of angels all around us who want to help us in all circumstances and at all times," the 40-year-old princess and Nordeng wrote in their introduction to the book "the Secrets of Angels".

"They are there for us. They are real. They exist," they added.

The book is a sequel to "Discover your Guardian Angel" which the two women published in 2009.

"In 'the Secrets of Angels' we reveal some of their secrets to make it easier for you to contact them. Angels want to be in touch with you, but it's important to know how they operate and how they get in touch," the women said.

The princess, who is fourth in line of success to the Norwegian crown, has renounced her title of Princess Royal along with most of her official duties in order to lead her own private life.

She is often mocked in Norway for having founded a "school of angels", but in an interview with TV2 to coincide with the book's release she welcomed the criticism saying it was a good thing "because we live in a free country where everyone can speak their mind".

In an article published in newspaper Aftenposten on Wednesday, doctor and commentator Jørgen Skavlan wonders why so many Norwegians have bought into what he describes as “latte metaphysics”

“We live in an ego-based society. It’s all about my soul, my development, my psyche, my head, and my self-realization. There are so many energies now that soon we won’t need light bulbs,” he writes.