Prince Harry and Meghan Markle were at the centre of an anthrax scare after a suspicious white powder was found in a 'racist' letter sent to their Kensington Palace home.

The letter was addressed to both Harry and Meghan at the Palace where the Duke and Duchess of Cambridge and their children also live.

The suspect letter prompted a security scare after it was intercepted by staff at the nearby St James's Palace. It did not reach Harry or Meghan - but they have both been informed of the incident.

Police have said they are treating the incident as 'a racist hate crime'.

Prince Harry and Meghan Markle were sent a package containing suspicious white powder

Counter-terror police and chemical experts were drafted after it was sent to the Palace on February 12, London's Evening Standard reported.

Subsequent tests later found the powder to be harmless.

The troubling incident came a day before police revealed a similar package containing white powder had been sent to the Houses of Parliament.

The second letter is understood to have been addressed to Home Secretary Amber Rudd. That substance was also found to be harmless.

The letter is understood to have been addressed to both Ms Markle and Prince Harry

Police are understood to be examining if the Westminster and Kensington Palace letters came from the same source.

A Scotland Yard spokesman said: 'Police are investigating after a package containing a substance was delivered to St James's Palace on Monday, 12 February.

'The substance was tested and confirmed as non suspicious.

'Officers are also investigating an allegation of malicious communications which relates to the same package. No arrests; enquiries continue.'

The incident has raised concerns about security at Harry and Meghan's Royal wedding on Saturday, May 19.

They will marry in a ceremony that is expected to last an hour, starting at midday.

The newlyweds will then embark on a carriage procession around Windsor before ending up at the town's famous castle.

Kensington Palace staff are said to have intercepted the package before it reached the couple

A reception will also be held at St George's Hall for the couple and the rest of the congregation before a private evening reception for close family, hosted by Prince Charles.

It is understood that there are no plans to change any of the details of the wedding in response to the latest security alert.

The alert comes after it emerged a suspected extremist had called on his followers to attack Prince George

Miss Markle will become an official member of the Royal Family following her wedding but she has already been given round the clock protection.

She will also have received a number of briefings on security and how she should react in a threatening situation.

The royal family has been the subject of a number of security alerts in recent years.

It recently emerged that a terror suspect had encouraged attacks on Prince George at his primary school in messages he sent out.

Louise Chantry - described as a 'royal superfan' - also tried to get into Prince George's school, prompting a review of the young prince's protection.

The 40-year-old former holistic healer was later given a caution, meaning she accepts wrongdoing but will not get a criminal record or face any further action.