Stella McCartney
Earlier in November the designer attended the 2015 British Fashion AwardsGetty

Stella McCartney has prompted speculation that she has allegedly had cosmetic surgery after a photo of her with a dramatically altered appearance was posted online. The fashion designer raised eyebrows due to a picture taken of her at a Christmas party at her Mayfair store.

In the image captured by Vogue international editor Suzy Menkes, her cheeks appear plumper and her lips fuller as she showed off a super-smooth complexion. Within minutes, a debate over her looks began raging on social media, with one Twitter user going as far as comparing her to a character from horror film Child's Play: "She looks like Chucky's sister. I'm shocked! What happened to growing old gracefully?"

Another commentator questioned "What's happened to her face," one user pointed out: "Come on guys, it's just the lighting."

While it could be argued that it was simply a case of bad lighting and unflattering make-up, medical experts claim the 44-year-old style icon has gone under the knife. Dr Mervyn Patterson, a cosmetic dermatologist, told IBTimes UK: "She is obviously a woman that has Botox regularly. You can't have a line-less forehead in your 40s without some help."

He notes that the most striking thing is her cheek augmentation. He alleged: "The most likely thing is that she has had had fillers in her cheeks. The problem with that is that when she smiles, you get that golf ball effect because there is no room for the cheek to move up to, the fat projects forward.

"Her lips have also been changed with fillers being used to plump up the lips. It's a little much because now when she smiles or animates her face, it looks unusual."

Dr Nick Percival of Cosmetic Surgery Partners claimed McCartney, who has dressed the likes of Gwyneth Paltrow and Beyoncé, might have also had chin augmentation.

"Her jawline looks more defined and the chin quite prominent. Her cheeks are also significantly fuller. This is the sort of appearance one could expect from a tightening of the lower face combined with chin augmentation and cheek augmentation. The combination produces a rather 'barbie doll' look in my opinion," said Percival, who has never treated McCartney.

IBTimes UK has contacted McCartney's representatives for comment and is awaiting a reply.

Stella McCartney is ready to roll out her holiday windows at her London store.

A photo posted by Suzy Menkes (@suzymenkesvogue) on