Tom Fletcher and Amy Dowden have tested positive for Covid-19 and will miss next week's live show on Strictly Come Dancing.
It comes just a day after the pair made their debut on the BBC dancing show.
The BBC said in a statement: "Tom Fletcher and Amy Dowden have tested positive for Covid-19. The pair are now self-isolating separately following the latest government guidelines.
"While they will both miss Saturday’s live show, Strictly Come Dancing protocols mean that all being well, they will return the following week.”
It comes amid a reported vaccine row brewing behind the scenes, where it is believed that three pro dancers have "refused" to get the vaccine.
Pro Amy, 30, was one of the first of her age group to receive the vaccine as she has inflammatory bowel condition Crohn’s disease.
She previously opened up to the Mirror about being trolled over being jabbed early, saying that people "type without thinking".
Three other professionals - who have not been named - are believed to be the only ones out of 18 who are not vaccinated this series.
A source previously warned that producers are "dreading" an outbreak of coronavirus on set - and news that one celebrity and their partner have already contracted the virus does not bode well for the rest of the series.
Covid previously caused havoc and the last series of Strictly and Dancing On Ice, which saw a number of couples pushed to leave the competition early after catching it.
Earlier today, McFly confirmed via social media that Tom had pulled out of performing at the band's concert in Glasgow this evening after falling ill.
They said in a statement: "Unfortunately Tom is unwell and won't be onstage with us tonight in Glasgow. He sends huge and heartfelt apologies to all the fans he won’t see tonight. The show will still be going ahead, we’re looking forward to seeing you all and need you guys to sing extra loud for us tonight."
Tom retweeted the band's message, adding: "So, so sorry."
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