An Uxbridge businesswoman had a huge surprise when she was plucked from the audience of a prime time TV show, and ended up on stage singing with international star Leona Lewis.

Joanne Stewart, 38, who lives in Ickenham , had no idea that colleagues and film crews had been capturing footage of her singing for weeks previously, to appear on Ant and Dec's Saturday Night Takeaway, aired on ITV on Saturday (March 12).

The karaoke-lover, who owns Leopard Lounge Hair & Beauty Hillingdon , was unsuspectingly sitting in the studio audience when Ant McPartlin announced a “bonafide superstar” was among them and introduced Joanne.

The Geordie duo called the segment 'Joanne Stewart: Secret Singstar' and joked that she was a global superstar with teams of fans, or 'Stewies', even producing two mock albums called Star in a Car and Songs from the Salon.

Dec joked about the recordings: “It's like having warm honey poured into my ears.”

Secretly filmed for weeks before the show

Telling viewers that "Stewie-fever was sweeping the nation", a video was shown with Joanne's version of Gabriella Cilmi's Sweet About Me played on radio, with Professor Green singing along in his car.

Joanne thought her colleague, Sam Frost, had won tickets and was taking her, and business partner Claire Fountain, along to the Takeaway show for an evening out.

But all along, Sam had been filming her with a secret 'handbag camera', while Joanne's husband, Lee had installed a dashcam to catch her singing along to songs on the car radio.

She told getwestlondon : “Sam had told me that she'd won tickets to the show to be in the audience of Ant and Dec and I love being in audiences so I was up for it - I love a bit of Ant and Dec!

“So I was just sitting there, innocently, and the next thing I knew they were dragging me down onto the stage and I was like 'oh my god I can't believe it, this is so embarrassing'.

“Ant and Dec were hilarious - they were taking the mick right out of me.

“They made out like I was this superstar and that I'd recorded these albums, which I'd obviously not done, and made out I was this superstar.

"The whole thing was hilarious but it was just so nerve-wracking.”

'Had no idea' Leona Lewis had joined the stage

Next thing Joanne knew, the comedy duo asked for a live performance, and the mum-of-two was made to sing Leona Lewis' Bleeding Love to the audience of 400 people.

She continued: “They basically bundled me onto the stage and I was like a rabbit in the headlights trying to read the words off the screen."

Meanwhile, as nervous Joanne sung her rendition, X-Factor winner, Leona Lewis, appeared to join the performance.

Leona Lewis cropped up to lend her vocals for an audience surprise to remember..

Joanne said: “I had no idea - I was so busy concentrating trying to get the words right that I didn’t even realise Leona had come in behind me.

“All of the crowd starting cheering and saying ‘Look, look!’ - so I turned round and there was Leona.

“I was so thankful she was there to help me with the song! My mouth had dried up, it was like I was in slow motion, it was really weird like I was in some sort of dream and I couldn’t take in what was going on.

“One minute I’m sitting in the audience, next minute I’m talking to Ant and Dec and they’ve bundled me onto the stage and there’s a superstar right in front of me!”

The spontaneous stitch-up stemmed from colleagues, Sam and Claire, receiving an email asking if they knew someone who was always singing.

Ms Frost said: “We immediately thought of Jo, being the karaoke queen that she is.

Joanne Stewart with her 'own' albums from the show

'Did herself proud'

Joanne has karaoke equipment at her house and all of Leopard Lounge's salons for children's parties, and never misses a chance for a sing-a-long herself.

Sam, head office manager, continued: “Jo herself is the original party girl and really is the life and soul, we thought she'd be the ideal candidate especially as she is always the one setting others up and making them do silly things.

“She did herself proud by singing live in front of 10 million viewers with the one and only Leona Lewis!”

Joanne was awarded an all-inclusive holiday for her family after the stitch-up, and has since been recognised by clients and at her children's school.

The salon owner said: “Me and the girls go on holiday together and last year I stitched them up by making them go out dressed as traffic cones - so it was only a matter of time until I was going to get stitched up.

“My daughter, Evie, has been singing Bleeding Love round the house since.

“Looking back on it, it was all so surreal; I couldn’t even speak let alone sing.

“ITV's producers said they had the best fun filming me and that I should have my own TV show!”

You can catch Joanne Stewart on Ant and Dec's Saturday Night Takeaway on ITV Player for 30 days after the episode.