There are controversial subjects, and then there is Mohamed. Yet the fear of controversy appears not to have deterred film-makers in Iran and Qatar, who are producing a pair of rival biopics of the seventh-century Prophet of Islam.As a protagonist, the Prophet poses a unique challenge: much of the Muslim world forbids his depiction on screen. The Iranian director Majid Majidi, whose $30m (£19.8m) biopic began shooting last October, reportedly intends to show parts of the Prophet's body, though not his face. While Iran's Shia population may be flexible about such imagery, Sunni Muslims elsewhere are not. Cairo's Sunni-led al-Azhar University has already demanded the unfinished film be banned.In December, in Sunni-majority Qatar, Alnoor Holdings, the media arm of al-Hashemi construction group, announced plans to spend $1bn on its own series of epic movies about the life of Mohamed. The team has hired the Islamic theologian Yusuf al-Qaradawi and Lord of the Rings producer Barrie Osborne as technical advisers.