Greek lawyers are threatening to sue the makers of film epic Alexander for showing the ruler as bisexual.
Director Oliver Stone says his film is historically accurate
The lawyers, led by Yannis Varnakos, said it is "pure fiction and not a true depiction of Alexander's life", and want this made clear to cinema-goers.
Colin Farrell, who plays the title role in Oliver Stone's new film, said: "Ambivalent sexuality was something of the times and part of the character".
Director Stone said there was a historian on set to ensure accuracy.
The film-maker added there was no question that the legendary ruler had "a polymorphous sensuality and was an explorer in the deepest sense of the word".
The lawyers have already requested that a credit is added to the start of the film to make it clear it is pure fiction.
Warner Bros and Stone have not made any direct comment about the request.
Mr Varnakos added that their campaign is "not against gays", but have promised to take further action if it is not made clear that the film is fictional.
The Gay and Lesbian Alliance Against Defamation (GLAAD) have welcomed the film, saying it breaks new ground for historical blockbusters, showing a man - Hephaestion - as the love of Alexander's life.
Alexander's place in Greece's history has whipped up controversy in the past.
Two years ago, a conference on the Macedonian-born ruler was stormed as a paper about his homosexuality was about to be presented.
The only overtly sexual scene in the film is between Alexander and his wife Roxanne.
She opens the scene by putting a knife to Alexander's throat after catching him accepting a ring from his male love interest Hephaestion.
The film is due to open in the US on Wednesday, and will be released in the UK on 7 January.