Lomu was hoping to force his way back into contention for the 2007 World Cup

The former All Blacks winger hurt his left shoulder during former England captain Martin Johnson's testimonial match in London on 4 June.

It was the 30-year-old's first competitive match in almost two years after receiving a new kidney last July.

The operation took three hours and he will remain in hospital for three days.

Lomu, whose arm will remain in a sling for eight weeks, had been named in a North Harbour squad to play Samoa on 22 June.

Team coach Alan Pollock had expected him to be declared fit for the match.

"Specialists advised that Jonah had to undergo surgery on his left shoulder," North Harbour team doctor John Mayhew said. "He will need a minimum of four months recuperation and rehabilitation following the surgery.

"It is an unfortunate rugby accident but we expect Jonah to make a full recovery."

He said the injury ruled Lomu out of appearing for North Harbour in this season's National Provincial Championship, which starts on 12 August.

Lomu, who said he hoped to force his way back in the All Blacks squad for the 2007 World Cup, signed a two-year contract with North Harbour earlier this year.