LONDON (CBSNewYork/AP) – Police in London are investigating a suspicious package that was sent to Prince Harry and his fiancee Meghan Markle.

A “package containing a substance” was delivered to St. James’s Palace on Feb. 12, according to the Metropolitan Police. Harry’s offices are located there.

Authorities tested the substance and determined it was “non-suspicious.”

Detectives are investigation “an offense of malicious communication” related to the package. According to London’s Evening Standard, the package contained a racist message.

Prince Harry and Markle are set to be married May 19 at Windsor Castle.

Earlier this month, a letter containing a white powder was sent to Parliament, which caused a partial evacuation.

That powder was also found to be non-toxic.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)