'The Masked Singer UK' Spoilers: Viewers Think The Fox Could Be A British Actress

The British edition of The Masked Singer has the nation putting on their thinking caps. Over the weekend, the U.K. debuted its first-ever season which was welcomed to an impressive 6.5 million viewers, becoming the highest-rated show of the day on any channel.

Last night, one of the contestants sang in a silver fox costume with a lot of energy. They appear to be female with a fiery tone. For their debut performance, they sang Blondie's iconic '80s hit, "Call Me." While they were singing, Ken Jeong said he thought they sounded like a performer and not a reality star. Davina McCall remarked that she thought she was amazing while Rita Ora said she loved her.

Fans took to Twitter to express who they thought was in the costume and used the show's hashtag, and they seem to be pretty sure that it's a certain British entertainer who has done it all, from acting in the West End to appearing in soap operas.

Warning: possible spoilers below.

"It's Denise Van Outen!! She danced to 'Call Me' on Strictly and she is known to have a good singing voice since she's done Chicago #MaskedSingerUK," one user wrote.

"Denise Van Outen collects teapots and she called her baby teapot before she was born... I get far to invested in this show!!!! #MaskedSinger," another shared.

"#SilverFox is Denise Van Outen. Too many obvious clues. The bed on stage too, signifying her days on The Big Breakfast with Johnny," a third account tweeted.

"Fox is totally Denise Van Outen #MaskedSingerUK," a fourth user remarked.

Denise Van Outen burst into the spotlight as a performer at a young age. According to London Theatre, at the age of 11, she starred in Les Miserables and played the character Eponine. Van Outen returned to the world of the West End in 2001 when she landed herself the iconic role of Roxie Hart in Chicago. Since then, she has continued to appear in multiple theater shows across the U.K.

Over the years, Van Outen has played parts in a couple of soap operas -- Eastenders and Neighbours -- and presented many TV shows including The Big Breakfast, Grease: You're the One That I Want!, and Who Dares, Sings!, to name a few, per IMDb.

At the end of the last episode, the contestant in the Pharaoh costume was voted out by the panelists. Former Home Secretary of the British Parliament, Alan Johnson was revealed to be the one under the mask, meaning viewers will have to keep watching to find out who Fox really is.