Simon Cowell has credited one Britain’s Got Talent act in making the talent show a global success – with it being sold to more than 30 countries.

Since the show started back in 2007 it has amassed a legion of fans with ratings topping 10 million viewers at its height.

The annual talent show, in which contestants compete for a spot at the Royal Variety Performance and a cash prize, will crown its winner tonight (May 31) at the live final on ITV1.

Now, head judge Simon Cowell has revealed who he credits for the show’s global appeal.

Cowell says that Susan Boyle was the act behind the true success of Britain’s Got Talent after she auditioned in 2009.

Boyle, of West Lothian, auditioned for the ITV series at the age of 47.

She took to the stage in front of a sceptical audience and judging panel - then made up of Cowell, Amanda Holden and Piers Morgan - and stunned them with her performance of I Dreamed A Dream from Les Misérables.

Cowell said Boyle’s audition in Glasgow came at a crucial time, as social media was just taking off and a clip was seen by more than 500 million people within a few days.

The performance led to huge demand for the show from TV channels all over the world.

Speaking to Deadine, Cowell said: “No one knew who this lady was. She was from Scotland, a little village, and she goes on Britain’s Got Talent and within 48 hours the clip had 500 million views.

“You have to think about that and go ‘it’s hard to describe, but it’s the most unbelievable feeling.’

Recommended reading:

“We sold the show to 30 more countries after that. It was unbelievable.”

Cowell had previously said Boyle’s audition is his favourite of all time and it taught him to “never judge a book by its cover”.

Boyle, now 64, was catapulted to fame after her audition and has since released eight albums and sold more than 20 million records.