Katie Holmes invests in organic hair care company

Actress Katie Holmes has signed up as a spokesmodel for an organic haircare company after investing in the brand.

The Batman Begins star became a big fan of Alterna after the company's products "transformed" her long locks, and now she has become a co-owner.

She tells WWD.com, "I love that Alterna uses natural and organic ingredients and stays away from harsh chemicals like sulfates and parabens. It's good for my hair and good for the earth, so I feel good using it.

"When it comes to hair, great style should be sustainable. Using the right products means you don't have to work as hard to look and feel your best."

Holmes will feature in new advertisements from February.

She is no stranger to the modelling world - she became the first-ever face of beauty firm Bobbi Brown Cosmetics in September, and previously fronted ventures for fashion firms Ann Taylor, Miu Miu and J.Crew.