Social media is up in arms over the idea of casting Hollywood superstar Leonardo DiCaprio as 13th-century Persian Sufi mystic, poet and philosopher Jalaluddin Rumi in a biopic.

Oscar-winning screenwriter David Franzoni, who will be helming the project, and with producer Stephen Joel Brown's dream cast: Leonardo DiCaprio as Rumi, and Robert Downey Jr. as Shams Tabrizi, a teacher and spiritual adviser to Rumi.

While critics have declared it a case of "Hollywood whitewashing", people on micro-blogging site Twitter reminded the writer that #RumiWasntWhite. People took to social media to vent their frustration and let Hollywood know that there exists a world beyond America.

The 13th-century poet is believed to have been born on the eastern outskirts of the then Persian Empire in present day Afghanistan.

David Franzoni, who wrote the script for 2000's Gladiator, has expressed his desire to "challenge the stereotypical portrayal of Muslim characters in Hollywood" with this biopic. But social media wants to know from him how he can challenge something he is promoting?

Reportedly, the 69-year-old screenwriter visited Istanbul to meet Rumi experts so that the team could start shooting next year.

The backlash to the proposed casting for Rumi biopic comes at a time when the #OscarsSoWhite controversy had some time back drawn attention on the lack of diversity in Hollywood.

Among some of the other casting choices made by Hollywood that have been criticised include almost the entire casts of both 'Exodus: Gods and Kings' and 'Gods of Egypt', Tilda Swinton being chosen as The Ancient One in 'Doctor Strange', Jake Gyllenhaal's turn as a not-so-Persian 'Prince of Persia', Alfred Molina and Christopher Abbott as Afghan characters in 'Whiskey Tango Foxtrot', and Scarlett Johansson being cast as a Japanese character -- Major Kusanagi -- 'in Ghost in the Shell'.