Lululemon is suing Costco over claims that the wholesaler is selling "knockoffs" and "dupes" of its popular athletic apparel at lower prices.

Lululemon accused Costco in the lawsuit of having "unlawfully traded" on its "reputation, goodwill and sweat equity by selling unauthorized and unlicensed apparel" that uses knockoff, infringing versions of its patents.

"As an innovation-led company that invests significantly in the research, development, and design of our products, we take the responsibility of protecting and enforcing our intellectual property rights very seriously and pursue the appropriate legal action when necessary," a Lululemon company spokesperson told Fox Business in a statement.

Lululemon claims that Costco’s Kirkland label makes hoodies, jackets and pants similar to its popular Scuba hoodies, Define jackets and ABC pants. Lululemon argues that this leads at least some shoppers to believe that the Kirkland-branded "dupes are in fact manufactured by the authentic supplier of the ‘original’ products."

The 49-page lawsuit shows alleged design and price differences between the companies’ products.

A screenshot of the Costco website included in the lawsuit shows a jacket the complaint describes as a dupe of Lululemon’s Hi-Tec Men's Scuba Full Zip jacket priced at $19.97. Meanwhile, the Lululemon jacket sells for more than $100.

Many of Lululemon’s hoodies and pants also retail for over $100.

Costco did not immediately respond to FOX Business' request for comment on Tuesday.

Lululemon is seeking an unspecified amount in monetary damages to "recover fully" any financial losses brought by the alleged dupes and is asking Costco to stop selling any products considered to be knockoffs.

Lululemon previously sued Peloton in 2021 over an apparel dispute. Two years later, the companies agreed to a five-year partnership.