A stage invasion took place during tonight's live X Factor show (November 8).

As Stereo Kicks performed their rendition of Michael Jackson's 'You Are Not Alone', Lee Nelson - the alter-ego of comedian Simon Brodkin - ran onto the stage before being escorted off.

All four judges praised the band for their professionalism during the incident, with Simon Cowell joking that Louis Walsh had added yet another member to the eight-piece group.

Mel B then revealed that Cheryl Fernandez-Versini originally thought the invader was Take That's Mark Owen.

An official spokesperson for The X Factor told Digital Spy: "During Stereo Kicks' performance this evening, there was a brief disturbance on stage, which was immediately dealt with by security. The performance continued as planned."

Nelson ultimately took responsibility for the prank in a series of Twitter messages, writing: "There are so many of them I thought anyone could have a go.