Eoin and Moley O Suilleabhain, an Irish musical duo who caught the attention of Russell Crowe and Steven Spielberg with their acoustic live performances, have landed a coveted part in his upcoming big budget film War Horse.

The film - which follows a young English farmhand who braves the trenches of World War I searching for his beloved colt, Joey - will display the two Irish brothers musical talents.

"We were shocked when we got the call," Moley told the press. "It was about 2.30 AM in the morning Irish time when the phone rang. I'd had a couple of drinks - so when he asked us to take part I was like: Oh, what date?."

An unlikely friendship between the pair and actor Russell Crowe which led to the Spielberg part began after they met the famously difficult Australian actor in County Clare.

"He liked our music and when he was filming in the UK we got back in touch and he asked us to come over and join him on the set of Robin Hood.

"We ended up going back for a barbecue with him on the lawn of his house and having a session alongside him and his wife and two children, all of his Merry Men, and Cate Blanchett and her children.

"Never in our wildest dreams did we ever think we would have ever been involved in any of that."

The name of the brother's group, size2shoes, was inspired by an American girl that Moley was "kind of seeing" who had very small feet. The duo say that now they've had interest from Hollywood they plan to record their second album in the US.