The ad shows a close-up of Portman’s face and the headline: "Dior show new look".
The ad was accompanied by the line: "Last-multiplying effect volume and care mascara. The miracle of nano brush for an unrivalled lash creator effect. It delivers spectacular volume-multiplying effect, lash by lash."
Dior made it clear to the Advertising Standards Authority (ASA) that it had not received any complaints from consumers, which it said demonstrated the ad "did not go beyond the likely consumer expectations".
Dior admitted that the ad, which had originally been created to advertise a lipstick, had been digitally enhanced in the post-production process to "tidy up" Portman’s eyelashes, replacing damaged lashes as well stylistically separating and extending them.
The brand did, however, provide consumer research that supported the ad's claims about the mascara, and stressed that Portman was not wearing false lashes, nor were false lashes added in the post-production process.
The ASA banned the ad because there was not "sufficient evidence" to show that the post-production retouching on Portman’s lashes did not exaggerate the likely effects of the product.
In February a L’Oreal anti-wrinkle cream ad featuring actress Rachel Weisz was banned following a complaint from Jo Swinson MP that it "misrepresented the results that the product could achieve".Follow @loullamae_es