McGoldrick has been a stand-out performer this season (Getty)

Full-back Ryan McGoldrick has signed a four-year contract extension with Super League strugglers Castleford Tigers.

The 27-year-old Australian-born United States international played both rugby league and union down under before joining Castleford in 2006.

"He's proved himself to be a tremendous capture for this club," said Tigers chief executive officer Richard Wright.

"We believe this to be a very significant deal for the Tigers. The fans will be delighted by this news."