Zac Efron sparks plastic surgery rumours on Twitter over 'new look'

"What in hell did Zac Efron do to his jaw?" one person asked.
"What in hell did Zac Efron do to his jaw?" one person asked. Photo credit: Facebook @MusicOnFacebook / Getty

Zac Efron's appearance in a video has prompted rumour he's had plastic surgery.

The Hollywood star made a cameo appearance on Bill Nye's 'Earth Day Musical' special on Facebook on Thursday (local time).

Efron, 33, immediately caught attention from fans after appearing to have a larger jawline and bigger lips than usual.

"What in hell did Zac Efron do to his jaw?" one person asked on Twitter.

"The group chat is trying to figure out if Zac Efron got lip fillers," another commented.

"I support anyone's right to get as much or little plastic surgery as they want, but Zac Efron, you were already hot, what did you do?" 

On Wednesday, a day before the clip was posted, it was revealed that Efron had split with his Australian girlfriend Vanessa Valladares.

The couple began dating last year after the 33-year-old Hollywood star met Valladares, 25, while she was waitressing at a Byron Bay cafe.

"Zac broke things off with Vanessa recently. It just didn't feel right for him anymore," a source told People.

"He is working and busy with several upcoming projects. He is happy, healthy and enjoying life."