In some circles, imitation is the sincerest form of flattery.

However, when it comes to fashion design, "knocking off" is a no-no -- especially to the folks at Oscar de la Renta.

Recently, an Oscar de la Renta employee saw a familiar pattern among the spring looks from Max Mara Studio, the Italian company's diffusion collection, reports WWD.

The tribal pattern was part of de la Renta's Spring 2008 collection (shown left). In addition, de la Renta claims jacket designs also appeared to be based on his work.

As "The Devil Wears Prada" fans know from Miranda Priestly's long-winded explanation about the fashion world working in a trickle-down way, lower-priced or more mass brands do take inspiration from the designer lines.

And it is standard practice for mills with original designs to offer a designer a one-year exclusive before putting that pattern back into rotation.

The problem here is twofold: Max Mara's take was most definitely not just inspiration, and more importantly, the mill that created the fabric for de la Renta and Max Mara didn't design the print -- de la Renta says he created the original artwork.

The Como, Italy-based Gentili Mosconi mill, however, does not believe it did anything wrong. "We have a commercial agreement with Oscar de la Renta for which he has the worldwide exclusive on our fabrics, whether designed by us or by him, for one year after which the designs are the property of Gentili Mosconi," owner and chairman Francesco Gentili told WWD.

As for Max Mara, a company spokesperson issued the following statement/apology: "The designers of the Max Mara Studio line chose the printed fabrics in total good faith. [In the Max Mara Studio collection] the prints are applied on different materials and fashioned in styles that are very different from the models designed by Oscar de la Renta.

"We will, however, speak to the mill that supplied the fabric, because we're very sorry for what happened. Max Mara asks its mills for a one-year exclusive on the prints it selects."

Oscar de la Renta did not return emails for additional comment.

Meanwhile, read about Juicy Couture's legal drama.