The Rhino performed Shotgun by George Ezra, with Fevola later admitting on social media, 'That's my favourite song - it gets me up'.
Whether Fevola genuinely let slip or was just just contriving a tacky FM radio stunt, the big clue follows mounting suspicions about other performers on the Channel Ten show.
Most people seem to think it’s Nikki Webster behind the alien mask. Her petite dimensions and singing style certain suggest that it is.
The former Sydney 2000 Olympics icon has broken her silence on the rumours, telling the Daily Telegraph’s Jonathan Moran, ‘I am so flattered.’
Speaking of the gossip that has even swept her popular dance studio, the 32-year-old former child star refused to rule out appearing on such a show.
‘I have seen a bit of talk and a lot of kids at the studio,’ she told the Telegraph. ‘Would I do a reality show like that? I don’t know. I guess it depends … right time, right place, it just depends.’
And Rob Mills has also been named. Radio producer Leon Sjogren tweeted a photograph of himself and the Wolf, and tagged the singer's name in the snap.
The producer from Fox FM's Fifi, Fev & Byron show posted the photo to Twitter and tagged Australian actor and singer Rob Mills as the Wolf.
There was no getting away from the blatant spoiler as Leon captioned the Twitter photo: "Me with @RobMillsyMills earlier today. #MaskedSingerAU."
Rob appeared on the first season of Australian Idol, he also played Neighbours' former villain Finn Kelly.