Many are convinced the mystery singer is Marti Pellow, the 58-year-old frontman of Wet Wet Wet. After his latest performance, social media was flooded with fans claiming they recognised his voice.

So far all fingers are pointed at Marti Pellow, the renowned Scottish frontman of Wet Wet Wet. Last week the Wolf's rendition of Billie Eilish's Birds of a Feather showed off a distinct vocal ...

One guessed: “This has convinced me tonight that this is def Marti Pellow”. Another added: "Definitely Marti Pellow, I recognise his voice anywhere”. A third chimed in: “This is defo scripted.