Fans have slammed Lady Gaga's 'completely different face' on the X Factor

Fans say Lady Gaga looks far too different for it not to be the result of plastic surgery.

X Factor viewers have gone wild on Twitter over Lady Gaga's "completely different face" after her performance on Sunday night.

Fans took to the social media site to question whether the Bad Romance singer had had a nose job or other surgery to alter her features, the Daily Mail reports.

Rather than complement the 30-year-old's powerhouse vocals on her new single Million Reasons, users slammed her "unrecognisable" looks - with one viewer even branding her an "imposter".

One viewer penned on Twitter: "How is that Lady Gaga? She has a completely different face! Who is this imposter?"

@ladygaga love your music but saying you have had no plastic surgery on your nose is a lie! Would admire you more if u were honest! #honest

— Heidi (@hilleardheidi) December 4, 2016

Lady Gaga's face looks like it's stuck with one expression lol lay off the plastic surgery

— Luis Castro (@luisdotdotdot) December 2, 2016

Apparently @ladygaga Has has surgery since last time she was on xfactor because she looks so different .... 😂

— My name isn't Alice (@monster4ev) December 4, 2016

However amidst the speculation were many fans praised the blonde superstar for looking incredibly well.

One wrote: "Wow Lady Gaga looks like she's had a her eyes lifted or a nose job. Can't decide. Face looking tighter than usual. Looking good though."

@FirozaULtiManag offered: "I think she's had cheek fillers n lips done. Looks amazing though".

The furore was created after Lady Gaga's performance on the X Factor before the tense sing-off between bottom two semi-finalists Matt Terry and Emily Middlemas.

The star took to the stage, belting out her hit Million Reasons against a dramatic smoky backdrop.