The filming of Celebrity Traitors is finally underway as the star-studded cast recently arrived at Ardross Castle in the Scottish Highlands. Production on the anticipated spin-off began this week, with the celebrities set to test their intuition as they try to uncover the treacherous group of traitors amongst them. A number of stars have been seen landing at Inverness Airport this week, including Jonathan Ross, Tom Daley, Charlotte Church, Stephen Fry, Alan Carr and David Olusoga. Other famous faces that are expected to feature on the new series are Good Morning Britain host Kate Garraway, rugby star Joe Marler, YouTuber Niko Omilana and Line of Duty actor Mark Bonnar. The line-up is rounded out by comedians Joe Wilkinson, Lucy Beaumont, presenter Clare Balding, EastEnders star Tameka Empson and beloved actresses Celia Imrie and Ruth Codd. In order to keep the secrecy surrounding the show, the BBC has enforced a number of strict rules on set. According to The Sun, the broadcaster has confiscated the celebrities' phones, with security watching over the stars so they don't collude with each other before filming begins. Ahead of the cameras rolling, the famous faces were kept apart in a hotel, with a source revealing to the publication that they aren't getting any special treatment. "The BBC aren't taking any chances with the contestants - even though they're household names. They are all holed up in a hotel together but they are being kept apart with a security guard on their floor at all times to make sure they're not swapping tactics or talking," an insider explained. "In the normal series of The Traitors, the contestants' phones are removed and there have been no special measures put in place for the celebs." They continued: "Some of them moaned about not having their phone but the BBC need to be sure they're not messaging or communicating on social media - so it's a total ban. Instead the BBC have a production phone for the celebs which they can use to make a phone call home, but a member of staff is never far behind. "The BBC want this series to be as explosive as ever, so they won't allow any collusion." Claudia Winkleman will be back to host the hit show, which first aired three years ago in the UK. There have since been a number of international series in the US and Australia, with the likes of Chrishell Stause, Dylan Efron, John Bercow and Ekin-Su Cülcüloğlu testing out their deception skills in the game. Celebrity Traitors will air on BBC One later this year