Cameron Diaz's rock sparks rumors of engagement to beau Benji Madden

Cameron Diaz has sparked rumors of her engagement to boyfriend Benji Madden after the actress was recently spotted flashing a gold ring on her finger.

Eyewitnesses told People Magazine that 'The Mask' star was just casually and constantly twirling her ponytail, showing off the ring and often playing with it at the Academy's Hollywood Costume luncheon.

The 42-year-old was again spotted with her gold ring going to celeb haunt Madeo in Beverly Hills with Madden.