Vickerman made his test debut against France in 2002 and went on to play 63 tests, but was forced into retirement by stress fractures in his right leg.
Australian Rugby Union chief executive Bill Pulver said in a statement “the rugby world is in shock after news of the tragic passing”.
“Dan was an uncompromising competitor who forged a wonderful international rugby career despite a number of injury setbacks along the way,” Pulver said.
“He cared deeply about the game and the players, helping players transition into life after rugby in his role with the Rugby Union Players Association following his retirement.
The 203-centimetre lock was born in Cape Town, South Africa and played for South Africa’s under-19 side in 1999 before moving to Australia and donning green and gold at the under-21 level one year later.
In 2001 he started what turned out to be an 86-game Super Rugby career with the Brumbies and Waratahs, and was called up to the Wallabies in 2002.
After the 2008 season, Vickerman took three years away from the sport, moving to England to study economics at Cambridge University.
Upon his return he played eight more times for Australia, with the 2011 World Cup semi-final loss to New Zealand his last cap.
The 2011 campaign was his third World Cup, adding to his turns in 2003 and 2007.
After leaving the sport, Vickerman worked in real estate and property investment. - ABC