Calling the filming day “disastrous”, Denyer revealed: “They were running three hours over and the audience had already been there for nearly nine hours for a record.

“It got so bad that the audience … started booing in the record. When the judges started pressing the buzzers, people were like, ‘Boo!’ They were revolting.

“The staff had to lock all the doors to the recording studio and they manned the doors and refused to let anybody out. People were trying to storm out and leave and say, ‘You can’t stop me!’ And they’re saying, ‘Yes we can!’”

In a statement to B&T, the production company that makes the show for Nine, ITV, said: “The records for the Knockout round did run over, as often filming does, but no one was held against their will and was free to leave as soon as it was safe to do so.

“The studio doors were not locked nor were exits blocked. Our priority and responsibility is the safety of the audience and crew in a working studio”.

According to Denyer, The Voice staff stood in front of the doors and blocked the exits, refusing to let people leave.

He continued by saying: “It got so bad that audience members started ringing the cops.

“They were calling triple-0 at the exits saying, ‘I’m being held against my will at Studio 3 in Fox studios at The Voice set.’”