Pippa Middleton Maid of Honor Pippa Middleton (R), the sister of Kate Middleton, leaves The Goring hotel with the Bridesmaids ahead of Kate's wedding to Prince William at Westminster Abbey, in London, April 29, 2011. Photo: REUTERS

Three years after Kate Middleton and Prince William tied the knot and the Duchess' maid of honor, Pippa Middleton, was made famous for wearing a formfitting dress to the royal wedding, the Duchess’ sibling is now being accused of wearing a "false bottom" to the April 29, 2011, affair.

According to a report from the Daily Mail, Stephane Bern, a well-respected French TV host, Knight of the Order of Grimaldi in Monaco, and expert on etiquette and the British royal family, accused Middleton, 30, of purposefully increasing her derrière's size for her sister’s big day.

“But of course she had a false bottom,” Bern, 50, said on his TV talk show on the France 2 channel on Monday, the Huffington Post UK reported. “I repeat it: She had a false bottom. You take her away from that and she has normal buttocks,” he added that her shapely figure, which was she widely praised back in 2011, was an “optical illusion.”

According to Bern, Middleton enhanced her figure, with the help of her now-iconic white Alexander McQueen dress, for the big day due to the intense media coverage surrounding the wedding's locale, Westminster Abbey, in London. “She knew there were a billion people watching. It was the moment to show it,” Bern said.

Pippa Middleton's "False Bottom"? Kate Middleton arrives with her father Michael and her sister, Pippa, at Westminster Abbey before Kate's marriage to Britain's Prince William in central London, April 29, 2011. Photo: REUTERS

Despite Berns’ claims, he did not specify what Middleton might have allegedly used to increase the size of her behind.

This isn’t the first time Middleton has been accused of augmenting her derrière. On the TLC network special “Crazy About Pippa,” one star, London spa owner Lesley Reynolds Kahn, shared similar sentiments. “I’m not convinced that it’s completely natural … If you look at other photos of her and you can see her in jeans, she’s got quite a flat bottom,” Kahn said. “But I think possibly for that day, for that gorgeous dress, she may have had some sort of pants that gave her a little bit of a lift, or even a little bit of padding."

Pippa, a normally private member of the Middleton family, commented on her much-discussed figure during a Women in Advertising and Communications dinner in London in February. “As I have found out, recognition has its upside, its downside, and -- you may say -- its backside,” Middleton said.