The letter was addressed to Markle and Harry, and delivered to the St. James Palace on February 12, according to the Evening Standard.
Mail sorters discovered the letter containing a white powder, and immediately alerted Metropolitan Police’s counter-terrorism command, who analyzed the powder and determined it to be harmless.
Investigators are also looking into a reported racist message that was to the package. The Met said in a statement to The Blast: "Police are investigating after a package containing a substance was delivered to St James’s Palace on Monday, 12 February." They added, "The substance was tested and confirmed as non suspicious." We're told as of now, no arrests have been made.
The newly engaged couple are scheduled to be wed on May 19. Security will no doubt be ramped up during the festivities.