“I will forever be fiercely proud of Jennifer Kent and of this film,” Franciosi tweeted on Tuesday.
“Unflinching honesty and truth.”
Franciosi, who was born in Italy and grew up in Ireland, later posted that “double standards in the industry are alive and well”.
The film, which screened on Sunday and Monday nights as part of the Sydney Film Festival, is set in colonial-era Tasmania and stars Franciosi as Irish convict Clare, who seeks revenge on a British officer for the atrocities he has committed.
Franciosi’s character is subject to the majority of the sexual assaults in the film, which also contains graphic murders.
At the Sydney premiere on Sunday at the Ritz cinema in Randwick, one woman walked out during the early stages, shouting: “I’m not watching this. She’s already been raped twice.”
Several people also walked out during the movie’s screening on Monday.
In a post-screening question-and-answer session on Sunday, director Jennifer Kent, who first rose to fame following acclaimed horror film The Babadook, told a reeling audience that “my commitment to cinema is just to make people feel something”.
In a statement to the ABC, Kent went on to say that while the film “contains historically accurate depictions of colonial violence and racism towards our Indigenous people,” it’s not “about violence”.
“It’s about the need for love, compassion and kindness in dark times,” she continued.
“Both Aisling Franciosi and myself have been personally contacted by more than a few victims of sexual violence after screenings who are grateful for the film’s honesty and who have drawn comfort from its themes.
“I do not believe this would be happening if the film was at all gratuitous or exploitative.
“We’ve made this film in collaboration with Tasmanian Aboriginal elders, and they feel it’s an honest and necessary depiction of their history and a story that needs to be told.”
The Nightingale has been praised on the international festival circuit, winning the special jury prize and best young actor for Indigenous man Baykali Ganambarr at the Venice Film Festival last year, where it was the only film by a female director in the competition.
Actress Aisley Franciosi is fluent in both Italian and English.
She is best known for playing the part of Katie Benedetto in the crime drama television series The Fall and her role as Lyanna Stark in Game of Thrones.