New Delhi, Aug 1 (ANI): R and B singer Rihanna has topped a new poll of the 'Sexiest Celebrity Stomachs in the World'.

The 20-year-old Barbados-born beauty, renowned for her revealing stage outfits, came first in the poll conducted by stomach-flattening supplement AntiBloat, reports China Daily.

Second on the list was Keira Knightley, who is famous for wearing midriff-flashing costumes, and who has bared her taut abs in movies including 'Bend It Like Beckham' and 'King Arthur'.

Dame Helen Mirren, who recently wowed onlookers with her trim physique when she donned a bikini while on holiday in the Italian Riviera, came third in the poll.

Sienna Miller, who showed off her enviable toned figure in a skimpy bikini while on holiday recently, shared the fourth spot with Liz Hurley.

Rounding off the top five was Jemima Khan, an English socialite known due to her relationships as Hugh Grant's ex-girlfriend, the former wife of Pakistani cricketer Imran Khan, and a daughter of late billionaire James Goldsmith.

The survey results reveal that a sexy stomach isn't governed by age, which is good news for all those wanting to tone up or maintain a flat tummy, AntiBloat spokesperson Jalal Janmohamed said.

Sexiest Celebrity Stomachs in the World:

1. Rihanna

2. Keira Knightley

3. Dame Helen Mirren

4. Sienna Miller and Liz Hurley

5. Jemima Khan (ANI)