A father has been left bruised and swollen after a circus trick involving a clown went badly wrong in front of his children.

Ben Garnham, 37, from Blackwood in South Wales, had taken his children on their first trip to the circus on Monday night when he was picked out of the crowd by the show’s clown to take part in the performance.

As his children filmed their father on stage, Mr Garnham, who works as a DJ, was accidentally knocked unconscious by the Circus Zyair clown.

“From what I remember, he didn’t explain what he was actually going to do. He said, 'Push against the back of my legs’ and that was the last thing I really remember,” he told the South Wales Argus.

In the footage Mr Garnham is seen being flipped backwards by the clown who then appears to land on his head. Two people rushed to the stage and together with the clown are seen carrying Mr Garhnam behind a curtain.

Mr Garnham regained consciousness shortly afterwards and was taken to A&E, where he was treated for concussion swelling on his face and a cut on the back of his head.

“I'm very angry at the way I was carried off stage before the paramedics even checked to see if I had any major neck or back injuries. I could of been paralysed for all they knew,” Mr Garnham said.

He wrote on Facebook that he felt he had to share the video “to show how I was manhandled while I was still unconscious”.

“I wasn’t asked to sign a disclaimer and it wasn’t explained properly when was going to happen,” he said, adding that he also felt sorry for the clown, who had called the next day to check how he was.

Mr Garnham has been offered a full refund and free tickets to the show by Circus Zyair.