Reality Tv star Kelly Osbourne has played down rumours she's secretly engaged to wed her boyfriend Matthew Mosshart.

The rock offspring was said to be "really excited" about exchanging vows after reportedly accepting vegan pastry chef Mosshart's proposal a few weeks before Christmas (12).

A source told Us Weekly magazine, "Kelly is the happiest she's ever been. Her career is going well, and she's in a healthy relationship with a wonderful guy."

However, Ozzy Osbourne's daughter appears to have denied the claims, simply writing on her page, "DontBelieveEverythingYouRead".

The former pop star, who was previously engaged to wed model Luke Worrall, first met Mosshart at the 2011 wedding of supermodel Kate Moss and rocker Jamie Hince.

Mosshart is the brother of Hince's The Kills bandmate Alison Mosshart.