The author claims that Princess Diana turned to a "revolving door" of "spiritual advisors" after King Charles' infidelity.

In a loveless marriage to the former Prince Charles, Princess Diana sought guidance from the mystical world.

According to Christopher Andersen, author of "The King," Diana had a succession of astrologers, faith healers, numerologists, tarot card readers, clairvoyants, psychics, and "spiritual advisors" over the years.

Andersen observed that her husband's old flame was the reason for his infidelity, as most people had informed her of this prior to her discovery.

"Over the years, Diana went through a revolving door supply of astrologers, faith healers, numerologists, tarot card readers, clairvoyants, psychics, and ‘spiritual advisors.' Most… told her what she already knew: that her husband was cheating on her with his old flame." — Christopher Andersen, author of "The King"

Simone Simmons' book, "Diana: The Last Word," was examined by Vanity Fair, prompting Andersen to make his remarks.

Diana's schedule was packed with appointments with psychics, spiritualists, astrologers, energy healers, palmists, tarot readers, and dowsers. Additionally, she frequently sought alternative medical treatments, such as colonic irrigation, reflexology, aromatherapy, acupuncture, and hypnotherapy.

According to the outlet, a former palace official stated that in the late '80s and early '90s, she was associated with a diverse range of individuals.

"In and out they marched, their arrival unknown, but once you witness that scene, it's an urgent plea for assistance."

According to author Tina Brown, bodyguard Ken Wharfe revealed that Diana was captivated by all these mad psychics.

But Diana had good reason to be worried about her husband.

In 1970, Charles Parker Bowles met through mutual friend Lucia Santa Cruz. Immediately smitten, Charles joined the Navy in 1971, despite a blossoming romance with Camilla. Despite not meeting the royal prerequisites for marrying an heir to the throne, the couple likely believed they didn't have a future together.

During his time in the Navy, Charles' younger sister Princess Anne's ex-boyfriend Andrew Parker Bowles married Camilla in 1973. Despite Charles' attempts to stop the marriage, the pair remained friends.

In her book "The Duchess: The Untold Story," Penny Juror previously stated that Charles and Camilla started an affair around 1978 or 1979, with Parker Bowles allegedly being aware. Despite their close relationship, Charles began dating Lady Diana Spencer in 1980. The couple eventually married in 1981.

"Richard Fitzwilliams, a royal expert, stated to Planet Chronicle Digital that Diana's use of psychics, clairvoyants, and healers has become infamous. He revealed that she was introduced to new age practices by Sarah Ferguson, who openly used them as therapies. Despite being able to connect with others, Diana was deeply insecure and unhappy herself, which led her to rely on healers and the like."

"Tina Brown revealed that she published her tell-all book "Diana: Her True Story" on the advice of astrologer Felix Lyle, who was connected to her intermediary James Colthurst, according to Fitzwilliams. This action marked the beginning of the destructive part of the war of the Waleses."

"Diana used holistic practices for support as her marriage fell apart. Those who frequently treated her made a lot of money," Fitzwilliams said.

Diana confided in astrologer Penny Thornton, expressing her desire to know if there was hope in sight.

In 1995, Camilla and Andrew Parker Bowles divorced, which was shortly after Charles admitted his relationship with Camilla in an explosive television interview.

In 1995, Diana, who was already separated from her husband, gave an interview to the BBC, stating that the marriage had failed because Charles was still in love with Camilla. She revealed that she was devastated when she discovered in 1986, five years after her marriage, that Charles had renewed his relationship with Camilla. As a result, she became so depressed that she intentionally self-harmed in a desperate attempt for help.

The princess remarked that the marriage, with three of us, was somewhat cramped.

Charles and Diana divorced the following year.

Diana remained committed to her spiritual advisors. Vanity Fair reported that Diana had a strong belief in the afterlife and communicated with the spirit of her grandmother, Countess Cynthia Spencer, whom she believed looked after her from the spirit world. The outlet also stated that Diana believed in a past life, she had been a nun and an ancient Christian martyr. She was afraid of speaking about her experiences out of fear she would be labeled "a nut."

According to the outlet, Diana was not solely focused on her own future but also on the futures of her sons, Prince William and Prince Harry. She frequently inquired about William's destiny and whether he would become king.

Simmons expressed worry about Charles' health, which consistently caused her concern.

Even Simmons believed that Diana was being exploited by "false prophets."

"Simmons wrote that Diana was one of the most insecure people he had ever met, and her inner pain led her to seek relief and comfort in unusual ways. He noted that there was hardly a therapy that she hadn't tried, some of which were beneficial, while others were quackery or even harmful."

Andersen claimed to Planet Chronicle Digital that Diana later received an ominous warning.

"Before her death, Diana requested a reading from her spiritual advisor Rita Rogers for her boyfriend Dodi Fayed. Diana wanted to know about the future and Rita claimed to have been visited by the spirit of Dodi's deceased mother Samira, who warned him not to drive in Paris."

"Andersen said that Rogers described seeing a tunnel, motorcycles, and a tremendous sense of speed. Rogers told Diana to warn Dodi, but she didn't realize Diana was in the car with him at the time. Rogers said she would have warned Diana as well, but she didn't see her in the car with him. Spooky stuff."

"Diana didn't require any assistance in the ESP field, as she accurately predicted in writing that she would likely die in a car crash, Andersen observed. She believed it would be a staged assassination that would appear as an accident."

In 1997, Diana passed away at the age of 36 due to injuries from a car accident.

WATCH: PRINCESS DIANA CALLED KING CHARLES A NIGHTMARE TO QUEEN ELIZABETH: AUTHOR

In his memoir "Spare," the Duke of Sussex described his encounter with a woman who possessed "spiritual powers."

"The 40-year-old was told by an unnamed woman that he was living the life his mother desired for him."

The woman mentioned that Queen Elizabeth's ornament was accidentally broken by Prince Archie.

The medium stated, "Your mother mentioned she chuckled slightly regarding that matter."

The Associated Press contributed to this report.