For decades, Winnie Madikizela-Mandela lived in the shadow of her husband, Nelson. But now, nearly four years after his death, Winnie’s own story – as the controversial, uncompromising activist who has been largely adored at home yet reviled abroad – is finally being treated as documentary-worthy in its own right.

Winnie, by British filmmaker Pascale Lamche, focuses on the grassroots campaigner in her political heyday. Featuring testimony from Nelson and Winnie’s daughter Zindzi as well as Winnie herself, now 81, it is one of a number of films emerging in African cinema that seeks to redress a long-held status quo – whether that’s about gender, race or politics.

For Lamche, who has made a number of films in and about South Africa, the prevailing narrative about the “rainbow nation” has long required that Nelson be the saint, and Winnie, the sinner.

“Patriarchy operates all over the world,” says Lamche, who won a Sundance directing award for her treatment of Winnie in the film.

“But what is really astounding in South Africa is that on both sides of the apartheid divide – with the white Afrikaner nationalists and the black nationalists – they agreed on what a woman should be, which is to be a wife and stay at home and toe the line. And of course Winnie never toed the line: she was volatile and uncontrollable, and that was punished.”

The film, which sold out two weeks prior to its showing at last week’s Film Africa festival in London, is in demand because it is told with a “particular nuance” thanks to its female director, says Sheila Ruiz, head of programming and partnerships at the Royal African Society, which organises the 10-day event.

“Winnie is a really powerful film because we get to be ‘inside’ Winnie, we get to feel as she might have felt, so on an emotional level it is quite close to what she may have experienced,” says Ruiz. “It really demystifies this negative image of Winnie Mandela as a troublemaker, as the antagonist of the saintly Nelson Mandela, and people want to hear her story.”

Long prone to cliches regarding gender, sexuality and social politics, African cinema is undergoing a seeming reboot in the way it treats those themes, says Ruiz, pointing to the increasing number of African female voices taking centre stage.

“I think it’s a historical balance redressing, where now more and more Africans are telling African stories, and more African women are telling African women’s stories. These are stories that need to be told, and up until a few years ago, they weren’t part of the mainstream.”

One such film is Raja Amari’s Foreign Body, which begins with a capsized boat full of migrants in the Mediterranean, and goes on to explore racism, misogyny, jihadism and longing, as told through the different immigration experiences of three characters.

For Amari, a Tunisian writer and director who emigrated to France, the “migrant experience” – as debated in politics and the media – is incomprehensible as a subject en masse, as migrants are all individuals with different goals and ambitions.

“I wanted to follow the journey of a young girl who is immigrating illegally and address how to be in a different land, and address your issues in a different land,” says Amari. “My characters come from the same background, from the same country, but they are also strangers to each other. They can confront or betray each other.

“I wanted to focus on how they deal with each other surrounded by this new context of the ‘fear of the other’, and the way that we can fear each other even when we are immigrants ourselves.”

Best known for Satin Rouge, her 2002 film about a Tunisian housewife who finds her feet as a late-night belly dancer, Amari says she has grown accustomed to sexism as she has promoted and screened her films – but believes that things are improving.

“As female filmmakers, it is more difficult to discuss sexuality, desire, and taboo subjects – the reactions are more vehement, as if we are not allowed to talk about the subject in this way,” she says. “But with Foreign Body, which was screened in commercial theatres in Tunisia, I felt a difference in the way the audience dealt with the film and with the subject. Despite what we think after the revolution, there has been a change – and that change is that there is more freedom of speech.

“There is a new dynamic now, and while we may not see it in the media, there are many new voices willing to speak out and who need to be heard.”

• Winnie will be broadcast on Netflix in February 2018