L'Oreal denied that her skin had been lightened amid rumours at the time.
But she says: "I'm sure they did because that's not the colour of my skin you saw in a few of the campaigns. I said to my agent, I'd like to see the pictures before, and I would like to be able to question them on colour correction."
The actress, who rose to fame in the 2008 film Slumdog Millionaire, signed up to be the face of L'Oreal in 2009 and claims she refused to endorse skin-lightening products.
"All the brands have a skin-lightening range in India and I made them put it in my contract that I would not touch that with a barge pole," she told The Guardian.