Winners and losers of previous series will come together for another chance to become king or queen of the jungle – or even to retain their crowns.
ITV did not confirm the famous faces, which have been reported by The Sun, and said more details will be revealed nearer the time.
Swash and Tufnell are reported to be joining the likes of Myleene Klass and Carol Vorderman as part of the cast, which is the biggest since the show began.
Filmed in South Africa, the series will air in 2023 with hosts Ant and Dec at the helm.
The cast is reported to include TV personalities Klass and Vorderman, as well as Diversity star Ashley Banjo, royal butler Paul Burrell and soap stars Andrew Whyment and Dean Gaffney.
The show will see former boxer Amir Khan joined by fellow sports stars Fatima Whitbread and Tufnell, as well as the return of more infamous cast members including Gillian McKeith and Janice Dickinson, with Helen Flanagan, Shaun Ryder, and Georgia Toffolo also reportedly set to return.
Among the contestants, Swash, Toffolo and Tufnell are looking for second wins after being in triumphant in 2008, 2017 and 2003 respectively.
Swash went on to host the ITV2 spin-off show: I’m a Celebrity… Get Me Out Of Here, NOW! and is married to fellow I’m A Celeb winner Stacey Solomon.
Cricketer-turned-pundit Tufnell took home the jungle crown after beating former footballer John Fashanu and interior designer Linda Barker.
All 15 contestants have earned their places after becoming fan favourites during their respective series, though some for better reasons that others.
During the 2010 series of the show, nutritionist McKeith, 62, fainted during a bushtucker trial, with Ant and Dec having to catch her before she was given oxygen.
Best known for her Channel 4 show You Are What You Eat, during her time in the jungle she became the first celebrity to refuse to attempt a bushtucker trial.
The food expert said she was on the “verge of mental exhaustion” when was voted to perform her sixth challenge, dubbed the Dreaded Digger, and walked away when she discovered green ants and cockroaches would be dropped on her head.
Former US model Dickinson became known for a string of bust-ups in the camp during her series in 2007, though she finished second behind Christopher Biggins.
A show spokesman said: “We’ll announce our line up and plans for I’m A Celebrity…Get Me Out Of Here! South Africa nearer its transmission in 2023.”
The rumoured celebrities have not confirmed their participation in the series.