Meghan Markle and Prince Harry were once sent a racist letter accompanied with an 'unidentified white powder,' write royal biographers Omid Scobie and Carolyn Durand in new book Finding Freedom.
The letter was intercepted by their security team as the couple traveled to Scotland a few months prior to their wedding.
Meghan and Harry "received an unusually high number of threats," the book adds, prompting an intensive security training for Meghan.
The training included coaching Meghan on what to do should she be kidnapped, and advised her on how to "develop a relationship with the enemy." The Duchess also had to learn "how to drive a car while in pursuit."
Although, Meghan was "grateful" to receive the security training, the whole experience was deeply distressing for her as she found it "extremely intense and scary."
The letter was filled with "racist musings," the authors added, as reported by the Independent.
Later, the white powder turned out to be harmless.
However it caused immense trauma to Meghan and Harry who were terrified as the former even struggled to sleep that night.