The estranged husband of Britney Spears and the King’s second cousin Lord Ivar Mountbatten have signed up for The Traitors US.

The third season of the reality show, which is hosted by Scottish actor Alan Cumming, has a similar format to the BBC psychological series and is set in a Highlands castle, but features celebrities instead of members of the public.

The show sees players divided into the “faithful” and a smaller group of “traitors” – whose goal is to eliminate the other contestants and win up to 250,000 US dollars (£195,785) themselves.

Sam Asghari, who was listed as an actor in the promotion for The Traitors US, and Spears tied the knot at a star-studded ceremony at the US singer’s home in Los Angeles in June 2022 after meeting on the set of the Slumber Party music video in 2016.

Their wedding was attended by high-profile celebrities including Madonna, Selena Gomez, Drew Barrymore and Paris Hilton.

Asghari and Spears announced their split in August 2023, citing “irreconcilable differences” in their court filings, and their divorce is reportedly set to be finalised later this year.

Lord Mountbatten is the son of the late Marquess of Milford Haven, who was the first cousin of the late Queen’s husband the Duke of Edinburgh, who died in 2021.

He was married to Lady Penny Mountbatten from 1994 to 2011, with their wedding being attended by the future Duke of Edinburgh and his now wife Sophie, Duchess of Edinburgh.

Lord Mountbatten and his former wife had three daughters, and he later came out as gay and tied the knot with airline cabin services director James Coyle following an amicable split with Lady Mountbatten.

She reportedly walked Lord Mountbatten down the aisle in 2018, and though not a working royal, he is the first member of the King’s extended family to have a same-sex marriage.

Palace Cycle Ride – Wessex
The then Countess of Wessex – now Duchess of Edinburgh – with Lord Ivar Mountbatten and tetraplegic cyclist Steve Osborne in 2002 (PA)

Lord Mountbatten has appeared in the ITV shows The Queen And Her Cousins With Alexander Armstrong in 2021 and Keeping Up With The Aristocrats in 2022.

The Traitors US has previously seen famous British faces take part, including former House of Commons speaker John Bercow and Love Island winner Ekin-Su Culculoglu, who both featured in the second series.

Also taking part in the third series are Vanderpump Rules star Tom Sandoval, Selling Sunset’s Chrishell Stause, RuPaul’s Drag Race winner Bob the Drag Queen, The Biggest Loser trainer Bob Harper, Summer House star Ciara Miller and WWE wrestler Nikki Garcia.

Other contestants include Zac Efron’s younger brother Dylan, Survivor competitors Carolyn Wiger, Jeremy Collins, Rob Mariano and Tony Vlachos, Real Housewives franchise stars Dorinda Medley, Robyn Dixon, Dolores Catania and Chanel Ayan, former The Bachelor spin-off stars Gabby Windey and Wells Adams and Big Brother US version stars Britney Haynes and Danielle Reyes.

Cumming revealed the cast in a video on YouTube, where he was seated in front of a fire and wearing a patchwork yellow suit.

He said: “This is sure to be the most treacherous season yet.”

The teaser also said the third season is coming soon to American streaming service Peacock.