Motsi Mabuse will miss tonight's episode of Strictly Come Dancing (21 November) in order to self-isolate.
Motsi took to social media to reveal she would miss the latest show on Saturday night.
The Strictly judge explained to fans that she had to make an "urgent" trip to Germany and would therefore need to isolate for 14 days on her return.
Motsi wrote: "Hi Guys - Earlier this week I needed to travel to Germany for an urgent reason. I will of course be following the UK Government guidelines and self-isolating for 14 days.
"I'll be watching from home and by the power of technology, should be in your living rooms. Watch out though, I'll be doing my own hair and make-up!"
Why Motsi's missing from Strictly Come Dancing
Motsi later revealed why she had to travel to Germany.
"Unfortunately we have no good news. Someone tried to break into our school @motsimabuse_taunustanzschule," she explained. "We are working with the police to solve this crime.
"We know we have been targeted on purpose and we will improve security in our school that this will not happen again."
A spokesperson for the show said: "Motsi had to make an essential journey and will now be isolating for 14 days as per government guidelines.
"We look forward to welcoming her back to the Strictly studio in a few weeks."
It's been confirmed that Anton will step in for Motsi for the next two weeks.
The BBC said Katya was asymptomatic and added: "As part of the protocols outlined ahead of the series, this sadly means they will no longer be able to take part in the competition"
"I’m absolutely devastated my Strictly journey has come to an end so soon," Nicola said of the news. "I had so much more to give and so many people to win this for!
"But I just want to say a huge thank you to Katya for being the best dance partner anyone could ask for. She pushed me way out of my comfort zone and it’s been an incredible experience.
"I’m gutted to be out of the competition but in these unprecedented times and as frustrating as it is, the COVID measures in place are to keep everyone safe, and I’m doing what I can to help.
The other couples will continue on with the competition as planned on Saturday night on BBC One.
Meanwhile It Takes Two host Rylan is also self-isolating after coming into contact with coronavirus.
Gethin Jones will step in for Rylan on Thursdays and Fridays while Zoe Ball will continue to host the show Monday-Wednesdays.