The 20-year-old star, best known for playing Hermione Granger in the Harry Potter films, doesn't understand why people would want to buy scents that are created by celebrities.

"I can't understand this fragrance thing - why would you want to smell like somebody else? Don't you want to smell like yourself?" she asked.

Emma added: "I've always had a strong sense of self and my convictions... That's why I can't understand necessarily wanting to look or be somebody else. Why don't people want to be who they are?"

The celebrity fragrance market is booming, with Katy Perry recently launching her debut perfume Purr and Katie Price promoting her third fragrance, Precious Love.

The actress, who reprises her role in Harry Potter And The Deathly Hallows: Part 1, prefers to put her own stamp on fashion, having modelled for Burberry and created her own range for ethical brand People Tree.

"Fashion is my way of expressing myself and who I am away from this role (Hermione)," she explained. "I felt it defined me so much that fashion became my way of telling people who I am. I never thought it would be something I would really get into, but it has become a real passion of mine."

She added: "I love it, and I will continue to work in the fashion industry. I am interested in ethical fashion, I want to make a difference and it's nice to contribute."

:: Harry Potter And The Deathly Hallows: Part 1 opens in cinemas on November 19.