The 40-year-old started out in league with the Brisbane Broncos, represented Queensland in the state of origin and won three caps for Australia.
Thorn moved back to New Zealand in 2001 and joined the Canterbury Crusaders, playing 12 tests for the All Blacks.
He went back to rugby league with the Broncos from 2005-07 but returned to union and the last of his 59 All Blacks appearances was the 2011 World Cup final in which they beat France 8-7.
Thorn helped Ireland's Leinster lift the 2012 Heineken Cup, becoming the first man to play in victorious World Cup, Super Rugby and European Cup teams.
He joined English Premiership club Leicester last year and has helped the Tigers climb to fourth in the standings.
"My goal was to play top-level rugby at 40 and to play well, and I've done that," Thorn told the BBC.
"I've been part of all these teams and it's been awesome but I just think maybe I should do something else."
(Reporting by Ed Osmond; editing by Toby Davis)
Share
