Blue were tricked into believing that bandmate Simon Webbe was about to die in an instalment of hidden camera show Tricked, according to reports.
Celebrities and members of the public are the victims of pranks carried out by magician Ben Hanlin in the ITV2 show.
The Sun said that boyband members Lee Ryan, Duncan James and Antony Costa were made to believe they were doing a photoshoot at the top of a cliff.
But they became terrified when Simon entered a caravan parked close to the edge and it began to roll.
Simon admitted he felt bad about tricking his bandmates, saying: "I felt like a traitor but it was a good test to see how much they love me!"
Meanwhile, Duncan was quoted as saying: "I felt sick to my stomach and helpless. I couldn't understand why he wasn't jumping out."