Kiwi Ultimate Fighting Championship star Mark Hunt has been handed a fight with world No 2 heavyweight Junior dos Santos in Las Vegas in May.

Hunt, who knocked out Dutchman Stefan Struve in his most recent fight in Japan last weekend, was touted as a combatant for dos Santos after his initial opponent Alistair Overeem pulled out of the May 25 fight with a knee injury.

Outspoken UFC president Dana White poured cold water on suggestions that Hunt could fight dos Santos at first, but the pair have agreed to an agreement overnight, handing the Auckland-born heavyweight the biggest fight of his UFC career yet.

Hunt, a former K-1 world champion, has a 4-1 record in UFC and hasn't lost a fight since September 2010.

However, dos Santos should prove a tough opponent for the Sydney-based Kiwi.

The Brazilian, who has a 9-1 record, was the UFC heavyweight champion between November 2011 and September 2012, losing his title to Cain Velasquez in Las Vegas.

The fight between Hunt and dos Santos will take place at the MGM Grand casino in Las Vegas.