Kylie Minogue wows in 'optical illusion' dress alongside lookalike sister Dannii in London - best photos

The singer arrived on the red – or in this case pale beige – carpet in a little black slip dress with an optical illusion twist. 

Kylie's black dress was outlined with white lace and fringe to create a shadow effect and slimming silhouette. 

The singer's dress split on both sides to reveal her pair of chic pointed-toe heels that matched her dress. 

"I like to keep the mystery," Kylie told HELLO! about her private life. "I am not a kind of 'here it all is…', I don't think I'll ever be that person. And I think for one's own sanity, you need to keep ... I mean, it probably sounds at odds as I’m sitting in front of a documentary poster."

The singer opted for a soft glam look on the night and styled her shoulder-length hair out in waves. 

Kylie's younger sister Dannii, who makes an appearance in the documentary series, stepped out to support her in London – and they both looked incredible!

Dannii wowed in a sparkling blue bodice and silky black skirt for the special occasion. 

Speaking to HELLO! about using anything family-related in her documentary, Kylie said: "Anything that had family in it? I sent it to them first. So, yeah, again, it’s been a process. If it was my archive, that was fine, but anything to do with family, I needed them to be okay with it."

Kylie reunited on the red carpet with her Neighbours co-star and ex-boyfriend, Jason Donovan, who appears for an interview in the documentary. 

The exes, who dated from 1986 to 1989, played Charlene and Scott on the Aussie soap opera and have remained close over the years.

Kylie shared a warm greeting with the star at the premiere. 

The exes posed for photos together on the red carpet. 

While appearing in the documentary, Jason is candidly open about his past romance with Kylie. 

"There's some clangers!" Kylie tells HELLO! with a laugh about the truth bombs Jason drops in the series.

She added: "It's just unreal. I just thought that's quintessential Jason Donovan. Maybe all of us, as we kind of go through life, become [bigger] versions of ourselves. I just thought that’s so JD. Swearing, telling it how it is."

"So I love seeing how he felt at ease enough to be really truthful, even when it was a painful conversation. I appreciated it so much," the singer said.

Smile for the camera! Jason joined Kylie and Dannii for a wholesome group photo. 

Britain's Got Talent judge Amanda Holden, 55, stunned in a silky yellow dress at the star-studded premiere. 

Louise Redknapp arrived on the red carpet wearing a monochromatic ensemble with a semi-sheer lace skirt. 

Radio broadcaster Clara Amfo opted for a bright striped maxi dress that draped to the floor. 

Love Island alum Tasha Ghouri looked effortlessly stylish in a flattering dress with attached sleeves.