LONDON (Reuters) - Wales dual-code rugby international Gareth Thomas has announced his retirement at the age of 37, his agent said on Tuesday.
Thomas started his career in union and played for Wales 100 times between 1997 and 2005, captaining his country and the British and Irish Lions before switching to league.
"We can confirm that Gareth Thomas is officially retiring from both international and club rugby with immediate effect," Emanuele Palladino said in a statement.
"This marks the end of a remarkable career for a remarkable person."
Thomas was due to play for Wales in rugby league's Four Nations championship which starts on Friday.
"I have listened to and discussed this decision with many of my family and close friends," Thomas said. "My mind has told me that the time to retire is now.
"If you can't give 100 percent to rugby then you can't do it justice. This is a sad day but I know that my time has come to an end as a player.
"My passion for the amazing game will never end or leave me," he added.
Thomas announced in 2009 that he was homosexual, the first professional rugby union player to do so.
He started his career at Bridgend and played for Cardiff, the Celtic Warriors and French club Toulouse as a quick and powerful fullback, winger or centre before joining Super League club Crusaders two years ago.
"Gareth hopes that through his achievements both on and off the field he has left a lasting legacy within the game," Palladino said.
Reporting by Ed Osmond, editing by Justin Palmer