Kate Middleton tried to keep the details of her wedding dress secret. But, a leak happened ahead of her and Prince William's special day, and it reportedly "threatened to ruin" the event.

Royal expert Katie Nicholl said that the leaked intel upset the future Queen Consort, likely causing tears at the Palace. Express UK noted that the expert made the claims on a Channel 5 documentary, "Secrets of the Royal Dressmakers."

As explained, the Duchess of Cambridge made an effort to keep the designer of her gown under wraps. However, the news got out, naming Sarah Burton of Alexander McQueen as the official designer of the iconic dress.

The information went public in the Sunday Times two months before the wedding day. Alongside naming the designer, the printed material, also, released the alleged "reasoning" behind Kate Middleton's choice of designer.

The publication reported that the Duchess of Cambridge selected Sarah Burton due to her "quirky elegance." In addition, "discretion and low profile," also, played significant roles in the decision.

Reports, later on, noted that the designer initially denied any involvement in the royal wedding. The public only obtained an official confirmation when it was announced on the day of the nuptials.

Moreover, Sarah Burton was present at the wedding to assist the Duchess of Cambridge before the ceremony.

The report seemingly first emerged on The Mirror earlier this week. It noted that the "big reveal" of the wedding dress still became "special" for Kate Middleton, as well as the public.

Designer Caroline Castigliano told the publication of this, adding that "even though the designer had been leaked," no one had laid eyes on the wedding dress before the wedding day. She pointed out that "everybody loved Kate's dress," and it "wowed" the public, especially when she stepped out, wearing the iconic piece.

Meanwhile, Town & Country said that the wedding dress was not only an Alexander McQueen hallmark, it was, also, Victorian-inspired. This is said to be especially true for the bodice as it featured the Victorian tradition of corsetry.

As for the lacework on the bodice and skirt, the Royal School of Needlework made them by hand. They utilized the Carrickmacross lace-making technique, which reportedly originated in Ireland in the early 19th century.

Kate Middleton had her "something borrowed" and "something blue" items, as well, for her wedding day. She wore the Cartier tiara, which Queen Elizabeth II owns, and a blue ribbon was sewn into the interior of her dress.