Even someone who believes in reincarnation couldn’t hope for this sort of cosmic luck.

Billy Campbell, the 4-year-old son of Australian TV host David Campbell, tells his parents he has the soul of philanthropist and beloved global figure Princess Diana.

Billy, who talks of being a princess “before the sirens came” was born 18 years after Di’s fatal car accident in 1997.

In a column for Stellar Magazine, Billy’s dad David writes that it all began when a then two-year-old Billy spotted Di on a card given to his mom Lisa, and said, “Look! It’s me when I was a princess.”

Dad alleges there’s no reason why Billy would have known such things. He and his wife Lisa maintain that there is no royal memorabilia at their home, and have rarely discussed the princess in their home.

According to David, a 3-year-old Billy knew a lot about Diana’s life, even referring to his “sons” Princes William and Harry. His father also claims Billy had recalled eerie details about Diana’s late older brother John, who died as a baby, a full year before Diana was born.

When he asked his son “Who else was in your family when you were a Princess?,” he says Billy responded, “I have brothers and sisters. I have a brother called John.”

David says he and his wife grew “pale” when they later found online that Diana indeed had a brother John.

One of the most detailed of the young boy’s recollections was when David says he “accurately described” the interior of Balmoral, the Queen’s Christmas holiday home.

“To a Scottish friend of ours, he claimed when he was Princess Diana he used to go to a castle in that kilted wonderland. He described the castle as having ‘unicorns on it’ and was called Balmoral,” David writes, pointing out that unicorns are the national animal of Scotland.

A moment that made Billy’s parents “stop in their tracks” was when his mom prompted Billy with a photo, who then told of Di’s tragic accident, saying, “There’s me as a princess. Then one day the sirens came and I wasn’t a princess anymore.”

David concludes the piece by asking, “Will Billy grow up and never remember this? Could he actually be the reincarnated essence of the People’s Princess?”