All Blacks coach Steve Hansen and New Zealand Rugby boss Steve Tew recently raised the issue.
They said they face the challenge of retaining players offered large salaries by Northern Hemisphere clubs.
The overseas deals are becoming more and more lucrative, with All Blacks first-five Beauden Barrett, who starred in Saturday's win over the Wallabies, reportedly offered $3.4 million a year to join a French club after next year's World Cup.
