So far the judges have all guessed Alfie Boe, Donny Osmond, Jason Derulo, Nile Rodgers, and Matt LeBlanc, but fans on Twitter have a different theory entirely, and it's all because of a QR clue.
Eagle-eyed fans noticed that there's a QR code on Robobunny's costume and some have managed to successfully scan it to see what secret is hidden inside.
One Twitter user shared what the code brought up, writing: "Just been watching the #maskedsinger and #robobunny had a QR code on the back which linked to this. Anyone else any ideas?"
Just been watching the #maskedsinger and #robobunny had a QR code on the back which linked to this 🤔 Anyone else any ideas? pic.twitter.com/iKcHZGGqUMJanuary 29, 2022
The image reads: "My royal barcode is 20019992003" which has led fans to believe these could be dates, and one savvy Twitter user believes they've cracked the code.
Putting two and two together, linking the word "Royal" with The Royal Variety Performance, one Twitter fan said that it's very likely it could be Westlife's Mark Feehily, who performed on those dates.
They explained: "#MaskedSingerUK #maskedsinger @ThisisDavina so after spending ages trying to scan the bar code on the back of robobunny and getting a royal barcode , tracking it to the royal variety show 1993, 2000 & 2003 I'm confident it's #markfeehily."
Other fans are agreeing too, with many absolutely convinced it's Mark based on this seemingly obvious clue. But is it a red herring?
#MaskedSingerUK #maskedsinger @ThisisDavina so after spending ages trying to scan the bar code on the back of robobunny and getting a royal barcode , tracking it to the royal variety show 1993, 2000 & 2003 I'm confident it I #markfeehilyJanuary 29, 2022
#MaskedSingerUK #MaskedSinger I’m so confused with Robo bunny. Been saying from the start Mark Feehily. That code is the years that #westlife were in the royal variety show 🤔 pic.twitter.com/CoePwdAc4CJanuary 30, 2022
I’ll put next months mortgage payment on Robobunny being Mark Feehily!! Knew it from 30 seconds into his first song!!! #maskedsingerJanuary 29, 2022
#maskedsinger robobunny is Mark Feehily 100%, absolutely no way it's not. And I speak as someone who was obsessed as a youngster and seen them live, all over the UK and Ireland, probably over 100 times 🤣🙊🤣January 29, 2022
While this theory seems pretty solid at the moment, fans won't know for sure until Robobunny is eliminated from the competition and finally unmasked before the judges.
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Lucy joined the WhatToWatch.com team in 2021, where she writes series guides for must-watch programmes, reviews and the latest TV news. Originally from Northumberland, she graduated from Oxford Brookes University with a degree in Film Studies and moved to London to begin a career writing about entertainment.
She is a Rotten Tomatoes approved film critic and has a huge passion for cinema. She especially loves horror, thriller and anything crime-related. Her favourite TV programmes include Inside No 9, American Horror Story, Stranger Things and Black Mirror but she is also partial to a quiz show or a bit of Say Yes to the Dress!