|Born||6 September 1979|
His first professional game was Workington Town v Featherstone Rovers on 8 September 2002. His first Super League game was Huddersfield Giants v Wakefield Trinity Wildcats on 15 June 2003. In 2006 Klein was named by the Rugby League International Federation as referee of the year. Klein was in charge of the 2008 Rugby League World Cup Final in Australia. He quit Super League in 2009 to return to Australia for family reasons.
On 17 February 2012 Klein was the referee for the 2012 World Club Challenge match between the Super League Grand Final winners Leeds Rhinos and NRL Grand Final winners Manly Sea Eagles at the Headingley Carnegie Stadium in Leeds which saw the English side run out 26-12 winners in front of 21,062 fans.
On 19 April 2013 he was the referee for the [[2013 ANZAC Test.