Copies of Charles Spencer’s Memoir About Sister Princess Diana Stolen in ‘Extremely Suspicious’ Break-In

Charles Spencer is facing an unexpected setback just days before the release of his highly anticipated memoir about his late sister, Princess Diana.

Several copies of 62-year-old Spencer’s upcoming book, Swan Song: Diana, My Sister, were stolen from a truck in the Netherlands, according to a Daily Mail report published Tuesday, September 15. The memoir, which is scheduled to be released worldwide on Tuesday, September 22, examines Spencer’s relationship with Princess Diana as well as her troubled marriage and the royal family’s response to her 1997 death.

The truck was carrying thousands of copies from a printing facility in Central Europe to a warehouse in the Netherlands when the driver stopped overnight in the Dutch countryside, according to the outlet. When the driver checked the vehicle at around 8 a.m., he discovered that someone had broken into it.

Despite the large shipment, only four copies of Spencer’s book were missing. The books had reportedly been wrapped in black plastic to conceal their contents, per the report.

“It’s extremely suspicious,” a publishing source said, according to the outlet. “Nothing like this has ever happened before. This is probably the biggest book of the year and the security surrounding it has been incredibly tight.”

Dutch police are investigating the break-in, while publishing insiders have floated theories ranging from opportunistic thieves to a highly informed supporter of the royal family, according to the report.

“Every possible precaution has been taken to prevent it from being leaked ahead of its serialisation,” the source said, per the report. “Therefore this unprecedented incident is being taken extremely seriously.”

The book is also expected to explore the tumultuous days that followed Diana’s fatal Paris car crash, including Spencer’s account of how the then-Prince Charles reacted to her death.

Per the Daily Mail, one publishing insider teased the significance of Spencer’s account, noting: “Earl Spencer has kept his silence for nearly 30 years and what he has to say about the King’s reaction when Diana died is utterly devastating.”

Spencer delivered an emotional eulogy for his sister at her September 1997 funeral at Westminster Abbey, which was watched by an estimated 2.5 billion people around the world.