A few months after the actor, musician and author Nakhane started receiving online death threats, he developed an unorthodox reaction to them. Call it a coping mechanism, but the 30-year-old could not help but assess the linguistic flair of his fellow South Africans. “It was interesting for my own people to describe in great detail how they wanted to kill me,” he says, softly. “But some of the descriptions were so poetic that I was like: ‘Hey, people can write. They can write, eh?’” He lets out a dry chortle, spiked with weariness, and leans in over his post-photoshoot glass of red wine. “It was poetic, but dark.”

He is a long way from home, sitting in a north London bar, but the ripple effects of the acting role that inspired graphic threats against his life still resonate. Nakhane stars in The Wound (Inxeba), a tender and intimate film that weaves one story, of male same-sex desire in rural South Africa, with another, about what happens when urbanised and queer teen Kwanda (played by newcomer Niza Jay Ncoyini) kicks back against ingrained tradition. It is a film so visceral you find yourself clenching your fists and wincing while anticipating the slap of violence during its most tense scenes.

But, really, the reason so much anger was directed at Nakhane, his co-stars and the director, John Trengove, was because The Wound features approximate depictions of ulwaluko – the secret rite of passage into manhood observed by the Xhosa tribe – and guy-on-guy sex scenes. Implying that the initiation, which involves circumcision, could have any proximity to homosexuality was more than some people could take. Add to that a white director telling a black African story and controversy followed the film at every turn. For Nakhane, who is still clumsily referred to as “openly gay” in the local press, that reaction seeped into his own life.

“Initially, people jumped to conclusions that the film would be some sort of exposé” – and he laces his next line with sarcasm – “because that would be interesting … They saw a trailer. They saw queerness. And they went nuts, because: ‘How dare you?’.” Outrage ensued, in verbal statements given by the Xhosa king, on the streets, in the media and on the internet. Nakhane recalls one protest at Wits University in Johannesburg: “There was a standoff between people on either side of the argument. This guy kept shouting about: ‘IF it’s true, IF this happens between men,’ and I couldn’t get him out of my head.” That is because Nakhane’s experience goes beyond the hypothetical. “I was propositioned. I” – and he points at his chest – “me. And not once. So I know from direct experience. And what’s next after that? To say that I’m lying?”

Nakhane (left) as Xolani in The Wound. Photograph: Allstar/Kino Lorber

He exhales these sentences with an animated passion, all hand sweeping and eye-rolls. He manages to be warm, even when recounting how one of his social media posts promoting the film spread a rage through his Xhosa community “like a wildfire”. His magnetic personality seems antithetical to that of Xolani, his character in the film, who maintains a secret love affair with Vija, a fellow caregiver to the teenage boys when they travel to a remote mountain for the initiation. “To prepare,” he recalls, “John said to me: ‘Imagine who you are and that everyone in the world loves you. It’s a warm day. Can you feel it?’ Yes, I could. ‘OK, so take that feeling, put it in a box and squash it. That’s where you are, as a character.’”

Although Nakhane speaks freely about his sexual orientation – largely at the prompting of journalists, it must be said – he, too, used to be closeted, like Xolani. He was born in Alice, once a model town for apartheid regime propaganda in the Eastern Cape, where heteronormative views ruled. At the age of 15, he moved to Johannesburg, and came out a few years later. He briefly reverted to a form of “pray the gay away” fundamentalism and lived in denial about his sexual preferences, but, by his late 20s, with a career as a soulful pop performer blossoming, he had accepted himself at last.

“Now, my sister tells me about friends of hers in school who were gay and out in grade 8, aged 14. And I’d ask how that was being received: ‘No one cares.’ I never would have dreamed, at 14, of being able to do that. Fourteen! I mean, I was feisty to come out at 17.” He laughs again.

While the film racked up awards, from the Durban and London film festivals to LGBT film festivals in Madrid, San Francisco and Lisbon, one branch of the Congress of Traditional Leaders of South Africa worked with the country’s Man and Boy Foundation to have it censored on its release in February. The Wound ended up with an X18 rating from the country’s censor, a classification generally reserved for porn – before its backers went to court in an attempt to have a less restrictive rating.

Speaking via Skype, Trengove reflected on a tumultuous ride. As a white director, he has dealt with another layer of backlash, from those who think he should not have told this story. He chooses his words carefully, pointing out how he co-wrote the script with Thando Mgqolozana and Malusi Bengu, both Xhosa men. “From the beginning, my own whiteness was a huge thing to reconcile, or at least grapple with, in the construction of the film,” he says. “The difficulty and discomfort of it is something I knew I was taking on. But the reasons for making the film under these circumstances outweighed those for not making it.”

He has watched The Wound prompt debate about race, tradition, what constitutes pornography, and gayness – in a country whose progressive constitution protects LGBT rights in theory, but less so in practice.

Nakhane (right) as Xolani and Bongile Mantsai as Vija in The Wound. Photograph: Allstar/Kino Lorber

All the drama surrounding the film, though, may distract from a simple fact: Nakhane’s performance is a delicate revelation. His past work as a musician and author (his debut novel, Piggy Boy’s Blues, was published in 2015) informs the emotional depths he plumbs in this first-ever professional acting role.

“He brought an understanding that, in order to do interesting work, you have to step outside your own comfort zone,” Trengove says. “It’s something a lot of actors struggle with, which he did very intuitively. And that is what you see in the film.” He adds: “There’s something incredibly expressive about Nakhane, a way in which what’s going on, on the inside, pours out of him. He has a translucency that I knew could work on camera.”

It beams out in person, too. When I ask how he reflects on the fever of the backlash, from this vantage point thousands of miles away, his eyes lock into focus. “Some people say: ‘Aren’t you tired of always having to talk about the fact that you’re a gay artist?’ and I’m like: ‘You have no fucking idea how tired I am of it.’ But for as long as I need to, I’m going to talk about it. Sure, it’s annoying that sometimes you see an article that splashes with ‘GAY MUSICIAN’, but do you know how many openly gay musicians there are in South Africa?”

He looks resolute, calm. “For as long as it needs to be said, then it needs to be said. For as long as there’s some kid out there who can’t be themselves, he’ll need someone.”

The Wound is in UK cinemas from 27 April.