A young unknown Irish actor has won a lead role in Transformers 4, Michael Bay has confirmed.

Director and producer Bay said that he spotted 20-year-old Jack Reynor in "a great little Irish movie", What Richard Did, which is out tomorrow.

In a post on his website michaelbay.com, the 47-year-old described Reynor as the “real deal”.

Bay wrote: “Jack Reynor… is an Irish kid that came to America with 30 bucks in his pocket. Pretty ballsy. Seriously who does that?

“This kid is the real deal.”

Expected to be released in the summer of next year, Bay also denied rumours that the fourth instalment in the sci-fi series would be a reset of the blockbuster franchise.

“Transformers 4, is not a reboot,” he wrote.

“That word has been floating around on the net.

“This movie takes place exactly 4 years after the war in Chicago. The story makes a very natural transition, and reason as to why we have a whole new cast.

“This Transformers will feel very different than the last three. We are embarking on a new trilogy.”