Package containing a 'substance' reportedly addressed to Prince Harry and Meghan Markle prompts anthrax scare The "substance" was deemed non-suspicious amid search for sender.

LONDON -- British authorities today said they are investigating a package containing a “substance” that was delivered last week to St. James's Palace in London, reportedly addressed to Prince Harry and Meghan Markle.

“The substance was tested and confirmed as non-suspicious,” the British Metropolitan Police Service said in a statement today.

“Officers are also investigating an allegation of malicious communications which relates to the same package.” Police did not reveal details such as the intended recipient of the package, delivered March 12, but several British media organizations have reported it contained white powder and was addressed to Harry and his fiancee.

Reportedly fearing at first that the substance could contain anthrax spores, chemical experts eventually deemed it to be harmless. The package reportedly never reached Harry and his fiancee, who were informed of the incident.

No arrests have been made, the police said in their statement today.

Authorities also are reportedly working to determine whether the incident is linked to a letter, also containing a harmless white powder, sent to the Home Secretary the next day.

Anthrax is an infection that is spread by exposure to a bacterium that is dangerous to humans. It has been used in attacks via letters with deadly consequences, most famously in the 2001 U.S. anthrax attacks that started a week after 9/11, killing five people and infected more than a dozen others.

Markle has already been assigned a security team from the Metropolitan Police Service’s Royalty and Specialist Protection Command.

Beefed up security will be in place during and in the lead up to the couple’s wedding May 19, which will include a carriage ride through the town of Windsor.

There have been sporadic threats against the wider royal family recently. In October 2017, there were online threats made against Prince George, the son of Harry’s brother, William.