Alexander McQueen is being sued for allegedly copying the design of a London-based bridal designer for one of the world’s most famous wedding dresses: Kate Middleton’s gown for her wedding to Prince William in 2011. Sarah Burton, creative director of London-based brand Alexander McQueen, who is responsible for designing Middleton’s gown, is named in the lawsuit, which was filed recently by British designer Christine Kendall.

According to the lawsuit, which is asserts claims of copyright infringement, Kendall submitted sketches of her idea for the dress to the Duchess of Cambridge before it was revealed that McQueen was chosen to create the gown. Kendall, who is the owner and designer of Christine Kendall Couture, claims she sent 1950s themed ideas to Middleton five months before the wedding and received a letter of gratitude from Prince William and Prince Harry in January 2011. A spokesman for Middleton – whose dress heavily referenced Grace Kelly’s wedding gown for her wedding to Prince Rainier of Monaco in 1956 – told the Sunday Times that the royal had never seen Kendall’s designs. Yet, Kendall claims Middleton’s stunning lace gown bears marked similarities to her sketches.

Kendall’s lawyer, of British firm Kuits, told the Sunday Times, “Our client is certain that her company’s design was unfairly taken and copied. The claim is not against the Duchess and there is no allegation of wrongdoing against the palace.”

According to a statement from McQueen: “We are utterly baffled by this legal claim. Christine Kendall first approached us at Alexander McQueen almost four years ago, when we were clear with her that any suggestion Sarah Burton’s design of the royal wedding dress was copied from her designs was nonsense. Sarah Burton never saw any of Ms. Kendall’s designs or sketches and did not know of Ms. Kendall before Ms. Kendall got in touch with us – some 13 months after the wedding. We do not know why Ms. Kendall has raised this again, but there are no ifs, buts or maybes here: this claim is ridiculous.”