Some of his fans were not happy with the fact that the sacred headdress was used as a fashion accessory in his UK Elle magazine cover.
The 'Happy' singer issued an apology, reported Ace Showbiz.
"I respect and honour every kind of race, background and culture," a representative of the Grammy winner said in a statement. "I am genuinely sorry."
Gwen Stefani had previously experienced the same thing when she dressed up as a Native American Squaw in No Doubt's 'Looking Hot' video.
The group later apologised to the Native American community and took down the video.