It's no secret that high street brands often duplicate runway collections for the mass market – but most designers are content to keep their mouths shut and have faith in the old adage "imitation is the sincerest form of flattery". Not so for Joe Bates, Sid Bryan and Cozette McCreery, the trio behind Sibling and Sister by Sibling. The eagle-eyed designers took to Twitter to express their displeasure when they spotted what seemed like a very familiar print on a Zara knit:

"It's not a fun game, TBH," the designers added in a later tweet.

The rose floral pattern overlaid with black dots originally appeared in the AW13 Sister by Sibling collection, and featured on a sequin cardigan as well as a crew neck top and skirt (you can take a closer look here).

Zara's version of the print appears on a slouchy sweatshirt as well as a full skirt. The two pieces appear to have been available in shops last year, although it seems that Sibling only cottoned onto the alleged knock-off today.

If Sibling's claim is true, Zara hasn't just knocked off their work. As the designers point out on Twitter, they worked on the print with Chad Wys, an Illinois-based artist who regularly uses drips, spots and stripes to obscure paintings and prints. 

Zara has become a go-to destination for stylists and other fashion insiders looking to buy close approximations of runway pieces, particularly those from labels like Jil Sander and Céline – not for nothing did a recent New York Times profile describe the Spanish company's retail offering as "Zalenciaga" and "Zéline". Last year, it made almost $15 billion in sales. 

Sibling has also begun to retweet messages of support from bloggers and fans like Susie Bubble:

What do you think – when does inspiration become imitation?