LONDON (AP) — London police say they are investigating a suspicious package that was sent to Prince Harry and his fiancee Meghan Markle.

The Metropolitan Police force says "a package containing a substance" was delivered to St. James's Palace, where Harry has his office, on Feb. 12.

It says the substance "was tested and confirmed as non-suspicious."

The force said Thursday that detectives are investigating an offense of malicious communication in relation to the package. The Evening Standard newspaper says it contained a racist message.

The prince and Markle are due to marry May 19 at Windsor Castle.

Earlier this month a letter containing white powder was sent to an office at Parliament, leading to a partial evacuation of the building. It also was found to be non-toxic.