When signing up for SAS Australia, most of the celebrity participants assumed the gruelling challenges that lay ahead would be the toughest part of the experience. But they soon learned they were only half the problem.
Actor Firass Dirani has been making waves in the camp, with his attitude having an impact on the physical tasks they all have to take part in.
When he plays up, they all get punished.
"I struggled with Firass' behaviour from day one," castmate Shannan Ponton tells TV WEEK.
"His smart mouth and back-chat sent the entire unit into a freezing creek, at dusk, while he stood dry and smug alongside the DS [directing staff]. In my eyes, a lame attempt at juvenile humour had ruined the first day."
Shannan, 46, thought the former House Husbands and Underbelly star's behaviour was down to "first-day nerves" and let it ride.
But when the 36-year-old's disrespectful behaviour continued, the former Biggest Loser trainer felt he had to step in.
"The entire cast were filthy, but many wanted to avoid confrontation and failed to speak up directly," he explains.
"I repeatedly addressed each event as it transpired. It was 'cooking' me, being punished unnecessarily at the end of a brutal and gruelling day.
"I'm never one to talk behind someone's back, so I spoke directly to Firass each time. His response was as puzzling as it was infuriating.
"With Firass, there was a total disconnection from reality, with him questioning whether the events and associated punishments even took place."
Shannan's own motivation for being on the show was to prove to his two kids you can do anything you put your mind to. But the fitness guru found someone deliberately trying to make life hell for everyone pushed him to the edge.
"On multiple occasions, I asked Firass to hand in his badge, as his presence and repetitive behaviour were ruining the entire experience for the rest of us," he says.