Speaking to STV, McElderry described how he initially feared the music mogul, but insisted that as he got to know him he realised he is "really nice".
He told STV: "I think he's a bit of a big softie. When I met him I was so scared, I remember the first rehearsal we had and he walked in the room and everyone [gasped] 'Oh!' and it just went silent.
"I used to have to think of things to talk about because I'd just lose my tongue straight away. But he's really nice, he is really, really genuinely nice. He's really honest and he's really nice, and he's not that scary in real life."
McElderry yesterday teased details about his debut album, which will be released in October.
