Former All Black winger Zac Guildford has signed a two-year deal with an option for a third with Top 14 leaders Clermont
Guildford, who is in his prime at 24 but has struggled with alcohol problems, will move to France after this year's Super 15 season.
"This is a tremendous opportunity for us to enrich our team with a player of such talent and versatility,"Clermont backs coach Franck Azema said.
"Like all the All Blacks we have in our ranks, we believe that he will bring us a bit of his culture, his feel for the movement of the game, which we want to continue to develop.
"Everyone knows his ability, technique, speed or the explosiveness that he can bring to the attacking line and we're really happy to offer him a new challenge and a first experience in France."
Guildford becomes Clermont's fifth recruit for next season after forward Sebastien Vahaamahina, centre Jonathan Davies, hooker John Ulugia and eighthman Fritz Lee.
New Zealand has a policy of not selecting foreign-based players for the All Blacks, meaning the switch could effectively end Guildford's international career.
He played the last of his 10 Tests for New Zealand in mid-2012.
Guildford's alcohol problems first emerged publicly when he was reprimanded by All Blacks' management during their 2011 World Cup campaign.
Just weeks later, after New Zealand had won the tournament, he had a meltdown while holidaying in the Cook Islands, running naked into a bar and punching two men.
Then in January last year he allegedly became involved in a brawl at a party in Christchurch, prompting him temporarily to withdraw from rugby and seek help.
Clermont sporting director Jean-Marc Lhermet hailed the arrival of a "fantastic" player of Guildford's level in central France.
"Zac Guildford's arrival is excellent news from our club," Lhermet said on the club's website.
"After having experienced nearly everything in New Zealand, it is with the ambition of living a new adventure and seeking new challenges that he joins the club for the coming seasons."