Princess Diana was spied on when she was still alive.

According to Nicholas Bieber, a journalist for Daily Star, the People's Princess was under surveillance by a secret intelligence agency which partnered with "Five Eyes," currently known as UKUSA, and "targeted" by the US's National Security Agency. They apparently built up a 1,056-page dossier on her. However, the documents won't be released as it was deemed "classified."

According to The Guardian, NSA later admitted that they had files on Princess Diana, but would never release it. "(They are) classified because their disclosure could reasonably be expected to cause exceptionally grave damage to the national security," the report read.

NSA told The Observer that although they held intelligence on Princess Diana, they never actively monitored her movements.

"The National Security Agency does not target British citizens, and any information that NSA holds that references Princess Diana is purely incidental to its collection," the spokesman said.

According to Bieber, Princess Diana was only among the celebrities spied by Five Eyes. Charlie Chaplin, former president of South Africa Nelson Mandela and Beatles legend John Lennon were also on the list.

Lennon's murder in 1980 shocked the world. The singer was shot outside his New York home by Mark David Chapman. There were rumors that he was killed by CIA.

In related news, according to Princess Diana's former butler, Paul Burrell, she suspected Prince Charles of plotting an automobile accident to kill her and marry Camilla Parker Bowles. The late Princess of Wales told Burrell about it months before the fatal car crash.

"Her words were 'these next few months, are the most difficult months of my life. I fear my husband is going to kill me. In an automobile accident. With head injuries. In order that he can remarry.' That is spooky. She predicted her own death nine months before she died, That is spooky. She predicted her own death nine months before she died," Burrell said.

On the other hand, author Sarah Whalen claimed that Princess Diana was indeed murdered. However, according to her, it was part of the "ancient actual ritual." She insisted that Princess Diana followed the footsteps of many royal women including Henry VIII's wives Anne Boleyn and Catherine Howard.

Princess Diana Princess Diana was reportedly placed under surveillance when she was still alive. Pictured: Princess Diana at Aintree racecourse for the Grand National on April 3, 1982. Photo: Getty Images/Hulton Archive