The video features a brunette bearing a remarkable resemblance to the 26-year-old singer.
But Carly has denied she is the X-rated woman in the clip, saying: "Discovered that someone put up a sex tape claiming to be me. Ridiculous. Obviously not me."
Just a few weeks ago the 'Call Me Maybe' singer was the subject of a nude photo scandal, which also turned out to be fake.
As if Carly has the time to be making home videos, anyway.
She's in the midst of a career whirlwind, most recently winning Breakout Artist and Choice Summer Song at the Teen Choice Awards on Sunday night.