RadarOnline.com has exclusively learned royal protection officers check in on Prince Harry and Meghan Markle's lemon and elderflower wedding cake creation every day and night at the London bakery where it is being made.

"Meghan and Harry's cake has become part of the daily duties of the special protection teams that guard the pair," a source exclusively told RadarOnline.com.

The same checks were carried out on Prince William and Kate Middleton's eight-tier fruitcake while it was under construction at a bakery.

While the special arrangement may seem odd, the "surveillance" is to ensure the design and slices of Harry and Meghan's cake — believed to be costing more than $25,000 — won't fall into the wrong hands.

Prince Harry, 33, and Markle, 36 — set to marry Saturday, May 19 at St George's Chapel in the grounds of Windsor Castle — opted for a lemon and elderflower cake with buttercream icing topped with fresh flowers to be made by pastry chef Claire Ptak, owner of London-based Violet Bakery.

"The bakery making the cake is grateful for visible security checks being made on the cake as they know thieves could be planning to steal it or its design," the source revealed.

More importantly, the police protection is also required to deter poisoners from targeting the wedding dessert.

"Security has increased ahead of the wedding as there are always fears ahead of any big royal occasion the risk of terror attacks will increase," noted the source.

Baker Fiona Cairns, who whipped up the fruitcake for Prince William, 35, and Kate Middleton, 36, recently revealed for the first time her creation was checked daily by local police near her bakery in Leicester.

"The team had to sign confidentiality agreements and couldn't tell their partners," said Fiona Cairns, 63. "We had over 80 people working in the bakery at the time, so we pretended we were preparing a wedding cake for a Harrods' window display."