Los Angeles: The huge diamond ring Miley Cyrus has been sporting lately has sparked rumours that she is engaged to beau Liam Hemsworth, but a source close to the teen actress has denied them.

On Saturday, the former "Hannah Montana" star, 19, stepped out with her Australian beau, 22, at Muhammad Ali's Celebrity Fight Night XIII event wearing a huge new diamond ring on her finger.

But, despite a flurry of speculation over the weekend, a source close to Cyrus has confirmed that the sparkler is not an engagement ring, as reported.

Cyrus has been wearing and showing off the ring for several days. The singer-actress displayed the dazzler in a Thursday tweet raving about a manicure. "I am soooo obsessed with @jennahipp nail foundations! It looks so chic and classic!" she wrote beneath the pic.

Cyrus and the "Hunger Games" star hit it off while filming the 2009 romance "The Last Song"; despite an August 2010 split, they reconciled less than a year later.

(Agencies)