He has accepted a request to join the coaching team from current Wallabies head coach Eddie Jones.
The Sydney newspaper reports that Hansen, who won the 2015 World Cup in England with the All Blacks, is working with the Wallabies in an advisory role as the team prepares for a warm-up match against France in Paris this weekend.
Hansen has been approached for comment.
The newspaper reports that Hansen will work with the Wallabies this week, ahead of their warm-up match against France. The paper also says Hansen, a friend of Jones, is not being paid for the work.
Hansen succeeded fellow world champion All Blacks coach Sir Graham Henry as head coach from 2012 to the 2019 Rugby World Cup where New Zealand lost to the Jones-coached England in the semifinals.
Ahead of that match, Jones said he had seen someone spying on his England team at a training session in Tokyo. At the time Hansen shrugged off suggestions the All Blacks were involved, saying Jones was creating "a bit of distraction" to take pressure off his own side.
"Eddie and I both know it’s all fair in love and war," Hansen said.
Hansen has the most wins of any All Blacks coach, coming away from a match victorious in 93 of the 107 tests in which he was at the helm.
A former police officer, Hansen coached the Canterbury provincial side 1996 to 2001, before working as an assistant to Wayne Smith and Robbie Deans at the Crusaders. In 2002, he joined the Wales coaching staff and was soon in the top job after Henry resigned following a poor Six Nations showing.
In his first season as head coach of Wales, they lost every match of the Six Nations, continuing into a 10-match record losing streak.
Facing the All Blacks in pool play at the 2003 Rugby World Cup, Hansen named a second-string Welsh lineup. His unfancied men performed bravely, scoring four tries and leading twice in the second half before the All Blacks ran 53-37.
He joined the All Blacks coaching staff in 2004, as an assistant to Henry and was part of the squad that was knocked out of the 2007 quarter-finals.
