The international charity has said that three print ads created by Giovanni FCB had never been approved by the organisation and should never have been entered.
The ads showed photos of injured people, including one with a Palestinian flag wrapped around his wound, and the copy accompanying the controversial image explained that MSF helps everyone, no matter what their nationality.
The charity feared that the political message behind the ad would compromise its neutrality. It said: "The ad was not approved by the organisation and had no authorisation to be entered in Cannes -- in fact, the entry was expressly forbidden."
MSF is an international humanitarian aid organisation that provides emergency medical assistance to populations in danger in more than 80 countries where health structures are insufficient or even non-existent.
Earlier in July, another Brazilian agency, DPZ, had its Cannes award for a poster for Johnson & Johnson's KY Jelly withdrawn, after the company said the agency had not worked for it for three years.
The medical charity won a Golden Lion award for work legitimately entered at the 2001 Cannes festival for a campaign developed by the Swiss office of Medecins Sans Frontieres by Advico Young & Rubicam.
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