The five-time Grammy Award-winner performed at the Royal Family's country retreat in Norfolk on Sunday, marking the Canadian crooner's only show in England this summer.

But concerns have been raised about Bublé, who is said to have been "almost falling over" on stage and "rambling in between songs" during the Heritage Live gig.

Michael Bublé supported Heritage Live Festivals’ sustainability mission by planting a tree in the Sandringham Garden (Image: Heritage Live Festivals)

Caroline Papworth, who was watching the 49-year-old with her husband, said she felt "something was off" with the singer during the show.

“I was close to the front of the stage with an excellent view of Bublé and when he came on, it seemed like something was wrong," she said.

"He didn’t........

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