Kate Middleton and Prince William 'Angry' and 'Frustrated' With Wild Conspiracy Theories About the Princess' Health: Source

Kate Middleton and Prince William have a bone to pick with internet trolls.

According to royal expert Katie Nicholl, the duo — who tied the knot in 2011 — have not been happy about all the rumors swirling about them online.

"Well, I know from the sources that I've spoken to that both William and Kate have been pretty shocked and genuinely surprised by the wild rumors that are circulating on the internet," Katie said about the conspiracy theories, which began after Kate had not been seen after her “planned abdominal surgery” in January.

"I think there's a sense of frustration, possibly even anger, certainly on William's part," the source added of the future King, who has been rumored to have a short temper.

The heir to the throne has apparently been trying to block out the noise in order to take care of his recovering wife and their three kids, Prince George, 10, Princess Charlotte, 8, and Prince Louis, 5.

"I think the suggestions that [Kate's] had, well, anything as crazy as a bad haircut that she's needed to grow out to cosmetic surgery that's gone wrong or people speculating that possibly she's in a coma, I think that has made the Prince of Wales frustrated, upset and pretty angry as well," Katie explained.

"It's been difficult for them. I think they're trying to ignore as much as they can. But, of course, this is a couple who have had to embrace social media. They've got an Instagram handle, they've got hundreds of thousands of followers. They certainly don't have their heads in the sand,” she continued. “They are aware of what is being written and what is being said. And I think there's a sense of frustration that they can't bring an end to it."

Katie added how the pair seem to know that the public will not stop until they see Kate "back to her normal, happy, healthy self."

The expert noted how the video footage obtained by TMZ of the Prince and Princess of Wales after they went shopping a mile from their Windsor home should have quelled the speculation, but it only furthered theories that Kate has a body double.

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"The TMZ video really should have quashed all of the fevered speculation about the Princess of Wales," she explained. "Her health, her recovery, and it simply hasn't. You would have thought that the video, which showed her walking at quite a brisk pace, carrying a shopping bag, looking pretty healthy and happy, and chatting in a very relaxed way with her husband, would have just dampened out all of the rife speculation that has really been circulating on the internet for weeks now. But, unbelievably, many of those theories are still circulating on the internet."

ET reported on Katie's remarks.