Hollywood studio Lionsgate is embroiled in an embarrassing row over Italian posters for the Oscar-tipped race drama 12 Years a Slave which herald the small role of Brad Pitt ahead of the film's main star Chiwetel Ejiofor.

Pitt is a producer on Steve McQueen's historical tale and also takes a small role as a good-hearted Canadian labourer. Ejiofor appears in almost every frame of the film as the real historical figure Solomon Northup, a free black New Yorker captured by slavers in Washington DC in 1841 and sold into servitude on the plantations of Louisiana.

The Italian distributors and marketing company behind the offending posters seem to have rather missed the point of the movie, however, with Pitt and another white star, Ireland's Michael Fassbender, elevated to prime position in publicity. Lionsgate, acting through its Summit subsidiary, labelled the offending material rogue and said it was doing its best to have it withdrawn.

"The 12 Years a Slave theatrical posters featuring Brad Pitt and Michael Fassbender that were recently released in Italy were unauthorised and were not approved by any of the producers or licensors of the film," a spokesperson told Variety. "Summit Entertainment, acting as exclusive sales agent for the licensors, is investigating and taking immediate action to stop the distribution of any unauthorised posters and to have those posters currently in the marketplace recalled."

Italian publicity for 12 Years a Slave featuring Brad Pitt. Photograph: Variety

Italy-based blogger Carefree Black Girl initially highlighted concerns over the posters, which separately display Pitt and Fassbender's images above a smaller image of a Ejiofor.

"I've been following the press for months and I can't wait to watch it but REALLY? I don't remember Brad Pitt being the protagonist of the film or having such a pivotal role in the story to stay in the middle of the poster," posted the blogger. "I sure don't know anything about marketing strategy to appeal audiences but isn't this going too far?"