Leona Lewis engaged to long-term love?

Leona Lewis has been spotted wearing a diamond ring, sparking speculation that she is engaged.

The singer was first seen with the sparkler as she left The Late Show With David Letterman in New York last week.

She was also snapped wearing it on a night out in London with fellow X Factor contestant Ashley McKenzie on Saturday.

Lewis has been dating electrician Lou Al-Chamaa, whom she has known for 14 years, since she was 17. The couple live together in Hackney, East London.

She denied reports that they were engaged last November, but previously said they planned to tie the knot in the future.