Beyoncé Knowles' marriage riddle

Beyoncé Knowles has fuelled rumours she is engaged to long-term boyfriend Jay-Z.

The 'Crazy in Love' singer - who has been dating record executive and rapper Jay-Z since 2002 - was with her beau at New York's Butter nightclub when fans spotted her wearing the diamond sparkler on her ring finger.

One eyewitness said: "She was wearing a huge diamond ring on her ring finger. When she noticed that I and some others noticed the rock, she quickly hid her hand.