Oprah and doctor Mehmet Oz, who frequently appears on her chat show, claim the public is being deceived into thinking the two have endorsed products like acai berry, a fruit touted as a miracle weight loss supplement, reported mirror.co.uk.
Their suit claims that following a show last year in which Oz discussed the Brazilian berry, internet ads started to feature images of him and Winfrey.
Products in dispute include cosmetics, anti-wrinkle creams and tooth whitening products.
The lawsuit was filed in Manhattan Federal Court Wednesday.
(Published 22 August 2009, 08:30 IST)