Improvisation comedy group The Noise Next Door and stand-up Mike Newall have both been a hit on Britain's Got Talent.

The Noise Next Door's off-the-cuff comedy song about Ant and Dec – "they're always ready to rumble" – based on the judges' suggestions impressed the audience and the judges, who were amazed that they were performing something that was not scripted or rehearsed.

David Walliams said: "It was hilarious."

Alesha Dixon said they made improv look easy.