The controversial Whitney Houston documentary… Didn’t she almost have it all?  

At one point during Nick Broomfield’s moving new documentary, Whitney: Can I Be Me, the singer pauses onstage during her 1999 world tour and gestures wildly to the wings. Slowly, hesitantly, her five-year-old daughter Bobbi Kristina edges into the spotlight and walks towards her mother, arms outstretched.

Instead of picking her up, however, Whitney urges her to sing a chorus she’d rehearsed, and dances wildly around the bewildered child, who stares slack-jawed into the yawning crowd.

“As you watch it,” Broomfield says, “you wonder what on earth is going on. It sort of creeps up on you subliminally, and a moment that first seemed quite sweet becomes alarming.”

It’s all the more poignant, of course, because both mother and daughter are now dead. After decades of drug use, Whitney drowned in a bathtub at the Beverly Hills Hilton in 2012, the day before the Grammy Awards. Three years later, Bobbi Kristina was found in a coma in another bathtub, in Georgia, and died shortly afterwards, at the age of 22.

But Broomfield’s documentary isn’t out to get Whitney: on the contrary, it’s out to rescue her from decades of criticism and misconceptions.

“She was the first really massive crossover artist, who paved the way for people like Beyoncé. With that responsibility came a lot of difficulties, and though I didn’t know that much about Whitney to start with, I just felt she was so condemned towards the end of her life, so under-appreciated, that it seemed a good time to look at her career again.”

Broomfield’s is not the only Whitney documentary we’ll see this year: Scottish director Kevin Macdonald is currently completing a film with the blessing of Whitney’s formidable mother, Cissy. But Whitney: Can I Be Me? is anything but authorised.

Once the Houston family heard about Broomfield’s film, “they sent this mass email out to everyone who had ever known Whitney, really from nappies, telling them not to take part. And I think with a lot of people it encouraged them to take part, because they thought the estate had behaved so badly towards Whitney, selling all (her personal items) off so soon after she died.”

Of course, Broomfield is not known for his use of official channels. A legend among documentary filmmakers, he has over the past 40 years or so challenged our preconceptions of everyone from rock stars to serial killers in films like Kurt & Courtney, Biggie & Tupac, and Aileen: Life and Death of a Serial Killer.

He’s often credited with changing the very nature of the genre by interposing both himself and the investigative process into his films. “I remember when I started,” he says, “I felt so restricted by that cinéma vérité way of telling a story, which ignored the other part of the story, which was all the shenanigans you had to go through to make it.

“The thing that compelled me to change was making a very unsatisfactory film about Lily Tomlin. She was preparing for this show, Search for Signs of Intelligent Life, which turned into this big hit,” he says, noting that the actress was resistant to certain parts of the process being filmed, and eventually sued them.

“I was so frustrated: we had all these great stories that we would tell our friends at dinner, and none of them were in the film. So on the next film, I thought, ‘I’m gonna put it all in as an experiment, and see if it works.'”

In the last decade of her life, Whitney Houston spent more time on the tabloid covers than in the charts, but in her pomp, there was no bigger singing star. Six Grammys, two Emmys, 200 million records sold worldwide – the statistics speak for themselves.

Remoulded as a pop princess by her handlers, she achieved the huge crossover success no other black artist had to that date, but her own community turned against her and felt her music was too ‘white’. Broomfield’s film captures the moment when she was booed by the crowd at the 1989 Soul Train Music Awards, a reaction that left her devastated.

Then, stories of drug use began to circulate, and her formidable cocaine and crack habits were widely blamed on her bad-boy husband, rapper Bobby Brown. But Broomfield’s film puts paid to that notion.

“I went to the street where Whitney Huston was born in Newark, and there was a crack house 10 doors down from where her house was.

“It’s probably worse now than when she grew up, but it was a rough area, you know, you had these terrible race riots in the 60s which she would have witnessed as a child – it was a tough, tough place. And there were a lot of drugs around… One of her brothers says in the film that he was 10 years old when he tried heroin. That’s the ambience Whitney grew up in.”

The director sees “no downside” in his film not being official.

Thanks to that intriguing footage taken on and off stage during her 1999 world tour (filmed by Rudi Dolezal, who is credited as co-director), we get to see her perform 14 songs live. And with an unsanctioned film, Broomfield says, “You can tell the story you actually believe to be there, rather than some party line the estate is putting together. Which would probably mean painting Bobby Brown as the bad guy, and cutting Robyn Crawford out of the story altogether.”

Robyn Crawford was a childhood friend of Whitney’s who became her inseparable companion during the 1980s. It’s been widely speculated that they were romantic partners, and the dogmatic and religious Cissy Houston was always antagonistic towards Robyn.

There was tension too between Robyn and Bobby Brown, which comes across in a fascinating scene where Bobby corners Robyn at a backstage party. Their contempt for each other leaps from the lens.

Having grown tired of being caught in the middle of jealous fights between Bobby and Whitney, as well as Cissy’s disapproval, Robyn quit as Whitney’s assistant in 2000 and the pair reportedly didn’t speak again.

Broomfield spoke to plenty of Whitney’s close associates and friends for the film, but neither Bobby, Cissy nor Robyn agreed to talk. “I feel that as a character, Robyn comes through very strong in the film, you have a real sense of who she is,” he says.

Broomfield thinks his film is “a very sympathetic portrait of (Whitney), and also of her relationships with Bobby and Robyn. I don’t feel it’s judgmental.

“She was a gladiator. I can’t think of another singer who would pump it out like she did – and it was just her up there (on stage), it wasn’t like Madonna who has this enormous thing with fairy lights and all going on around her. It’s just Whitney, sweating and sweating, pushing herself, giving it all.”