She may be only 29, but Kim Kardashian has admitted using Botox.

As the reality TV star strenuously denied rumours she had undergone plastic surgery, she opted for a cheaper alternative - the face-tightening high ponytail, dubbed the 'Croydon facelift'.

After wearing the harsh style as she shopping in Los Angeles yesterday, Kardashian decided to keep her hair up as she attended a Hollywood party with her family.

From dressed-down to dazzling: Kim Kardashian looked casual in a studded vest and jeans (right) before changing into a Sass & Bide dress for a TV party

As she shopped at the Nordstrom department store on Monday afternoon, Kardashian looked far from her usual glamorous self in a loose-fitting black studded vest and skinny jeans.

But it was a different story at the 20th anniversary party of the E! channel later that evening, as she showcased her famous curves in a tight-fitting £1,485 white Sass & Bide mini-dress.

The dress, which is available in both black and white, has been spotted on several celebrities in recent months, including Beyonce, Charlotte Church and Kardashian's friend, former Pussycat Doll Melody Thornton.

Natural: Kardashian denied she had butt implants, or any other plastic surgery, on U.S. TV show Nightline

She was joined by her sisters Khloe and Kourtney and mother Kris Jenner.

Writing on her Twitter page: 'Heading to E! Entertainment's 20th birthday party with the whole family. Damn I feel old.

'Me, Kourtney, Khloe and my mom all showed up to the E! dinner in sequins! All accidental! Sooo embarrassing! We all look like twins!'

The Kardashian family night out came as the foursome were interviewed on ABC News show Nightline.

Croydon facelift: Kardashian's tight ponytail looked harsh with her delicate features at she left Nordstorm

While Kardashian denied she had undergone plastic surgery, she admitted using Botox.

She said: 'I'm totally not against plastic surgery. I've tried Botox before. That's the only thing that I've done.'

Famous for her curves, and in particular her derriere, Kardashian insisted it was all natural: 'No butt implants, no butt injections, no anything to my butt.

'I've never had my nose done. What's funny about my nose, it's my biggest insecurity. I always want to get my nose done.

Family affair: Kardashian joined her younger sister Khloe (1st left), older sister Kourtney (2nd left) and mother Kris Jenner (right) at the party

'I went to the doctor, I had them take the pictures, he showed me what it would look like and it just didn't - I wouldn't look the same.'

Talking about her cleavage, Kardashian joked: 'Trust me honey, if I take this bra off you will tell me I need to get them done.'

While Kardashian insists she was surgery free, her older sister Kourtney, 30, and mother Jenner, 54, have both had breast enhancement.

Model monent: Swimsuit model Marisa Miller (left) and Playboy Playmate of the Year Hope Dworaczyk

Colourful: Singer Kelly Rowland wore an eye-catching multi-print dress (left), while One Tree Hill actress Sophia bush wore a blue and purple bandeau creation

Kourtney said: 'I have had breast implants, but it's so funny 'cause it's not a secret, I could care less.'

Jenner added: 'Nothing ever on my face. I've had my boobs done and that was 1988 and I had it done twice in the same year because the first one didn't work... I had some Botox.'

Kardashian also admitted she was still really close to her ex-boyfriend, American football player Reggie Bush, who she split from in March.

She said: 'We're really good friends. We're in contact all the time. It's just, the relationship isn't for us right now so I'm totally happy and fine.'

Back to reality: Dancing With The Stars professional Cheryl Burke (left) and The Hills star Stephanie Pratt