The singer was appearing at the Global Citizen Event, alongside Coldplay, Beyonce and Ed Sheeran, on Saturday (26Sep15) when eagle-eyed onlookers noticed the ring.

Neither he nor fiancee Grace Miguel have commented on the rumours, but Grace posted an image of the words "So Very Thankful" on on Saturday.

It was reported on Wednesday (23Sep15) by American publication Us Weekly that the pair had eloped at the beginning of September (15), and honeymooned in Havana, Cuba.

Usher's first marriage to Tameka Foster ended in 2009. The pair was embroiled in a bitter custody battle for three years over its two sons, ending with the singer winning sole custody. Usher and Grace have been dating since 2009, and got engaged in January (15).