Speaking at the Edinburgh International TV Festival, Spence did however admit that some scenes were restaged for the cameras.
"It's not scripted," he said. "There are moments that we do act, or they say, 'Can you do that again?' But we're all performers in that building."
Spence insisted that his on-screen persona as well as that of his co-star Andrew Stone were genuine.
"[Andrew] totally is for real," he claimed. "He's absolutely not exploited."
He added: "It was really important that people didn't dictate to us how we were going to be portrayed. [That's] the reason our documentary has been such a hit."
Spence is currently working with Sky1 on a new reality series.