The German designer unveiled his new activewear line, Plein Sport, in Milan last month (Jan17), with the presentation including a catwalk set up like a race track and athletes jumping over ramps in the middle of the stage.

While it was quite the spectacle, it appears the ideas weren't 100 per cent original, as Wang pointed out in a post on his Instagram account on Tuesday evening (14Feb17).

The fashion star put a clip of his H&M presentation from three years ago next to footage from Plein's recent show, with a series of stark similarities evident, from the track set-up and sports accessories to the activities that took place during the event.

"Can I copy your homework?" he captioned the clip. "Yeah just change it up a bit so it doesn't look like you copied."

Even the final bow from the designers is very alike, as Plein also ran out onto the runway like Wang did.

This isn't the first time Plein has found himself in hot water with other labels; in January (17) French leather goods brand Perrin Paris accused him of copying its "glove-clutch" design, filing a lawsuit against him.

Chief executive officer Michel Perrin told WWD: "It's the exact duplicate, same size, same design, same concept - the hand receiving portion of our bags that we design-patented. They only added a skull... It's the heart of our business."

And in December (16), Dolce & Gabbana claimed Plein had been poaching staff, as he shared the legal documents from the iconic label on Instagram himself. It was alleged that staff from Philipp Plein International contacted around 10 of D&G's employees to offer them work at the designer's Milan showroom.

Plein responded to the accusation and tagged Stefano Gabbana in his post, going on to state that people can choose where they want to work. He also noted that "everybody loves you until you become competition".