Fans livid with Rihanna's 'slurry lip-synching' Singapore concert

Rihanna's fans slammed her performance at the F1 Grand Prix in Singapore for being 'disappointing', on Twitter.

Fans accused the 25-year old Barbadian recording artist of being drunk and high on weed, and even 'lip-synching' during the show, Radar Online reported.

Recently, the 'Diamonds' singer was criticized for posing with an endangered primate and visiting a live sex show during her vacation in Thailand.