London: Singer Miley Cyrus has dismissed rumours of undergoing breast enhancement surgery.

The 19-year-old was spotted with a fuller figure during Cnn Heroes event in Los Angeles Dec 11 and fans speculated that she has gone under knife, but Cyrus is adamant she's all natural, reports a website.

"Thank you for the compliment but they are all mine. I wish they'd realize (sic) you don't have to be fake to be beautiful," Cyrus posted on micro-blogging site Twitter.