Lululemon is suing Costco alleging the wholesale retailer is selling knock-off, or 'dupe' versions items baring its trademark protected designs and marketing terms.

Lululemon is accusing Costco of stealing from its "path-breaking" brand by selling dupes of its sweatshirts, jackets and pants.

Lululemon alleges that Costco has stolen the intellectual property of its Scuba hoodies and sweatshirts, Define jackets and ABC pants.