The Freeport-based retailer is accused of intentionally and willfully plagiarized a patented 'heel cup' that is featured on millions of Skechers shoes.

Skechers insisted in its filing that its designs are "unique and eye-catching" because they use "graceful, sweeping, gently rolling lines and slopes" that make the footwear appear like a real heel. It noted that it wasn't until it introduced the shoe that L.L. Bean began selling a similar model.

LL Bean has been sued by footwear maker Skechers USA, which accused the clothing and outdoor gear company of illegally copying its shoes, which have sold in the millions. According to a complaint filed late Monday in Manhattan federal court,

NEW YORK - Footwear and apparel company Skechers has filed a lawsuit against retail company L.L. Bean over alleged illegal shoe design copying. The suit was filed Monday at the U.S. District Court, Southern District of New York. According to a complaint obtained by FOX Television Stations, Skechers is suing L.L. Bean for patent infringement.

Skechers asserts that LL Bean entered the market with its infringing shoe only after Skechers had invested significantly in developing and promoting its designs, which have gained broad appeal.