Sydney - Former All Black wild man Zac Guildford on Wednesday joined the Waratahs for the 2016 Super Rugby season, the New South Wales club said.
The 26-year-old, whose career has been blighted by alcohol problems, will leave Hawke's Bay Magpies for Australia's 2014 Super 15 champions on a 10-month contract.
Waratahs head coach Daryl Gibson said the New Zealander would compensate for the recent loss of a number of senior players including veteran outside back Adam Ashley-Cooper who heads to France after the World Cup.
"I felt like I needed a ready-made player who has been proven at Super rugby level," said Gibson.
He acknowledged that Guildford faces a challenge to fit in after several tumultuous years which have seen him lose his All Black jersey.
"I've spoken with Zac extensively and he is prepared to earn the respect of his teammates through his actions, and to uphold the values of our club," Gibson said.
"He's probably been carrying that 'bad-boy' baggage around with him for the past few years, and from my observations he has moved past it and grown up a bit."
Guildford walked out of a contract with French Top 14 side Clermont in May citing "personal reasons".
"Of course his signature comes with risks for both parties, but we strongly believe in his ability and will support him," said Gibson.
"He's highly motivated and aspirational about his career - so our challenge will be to get the best out of him."
Guildford played 11 Tests debuting against Wales in 2009, and was a part of New Zealand's 2011 World Cup-winning squad.
Alcohol problems first emerged publicly during the tournament, when he was reprimanded by All Blacks' management.
Just weeks later, he had a meltdown on holiday in the Cook Islands, running naked into a bar and punching two men.
Then in January 2013 he allegedly became involved in a brawl at a party in Christchurch, prompting him temporarily to withdraw from rugby and seek help.
Personal tragedy struck in 2009 when his father died of a heart attack while watching from the stands as Guildford and his New Zealand teammates won the Junior World Cup in Tokyo.
He launched his Super Rugby career with the Hurricanes in 2008, playing 18 matches before moving ahead of the 2010 season to the Crusaders where he won 61 caps.
Guildford has also represented New Zealand Maori and New Zealand Sevens, winning a 2010 Commonwealth Games gold medal.