The Englishman hailed for Fiji's gold medal success at the Rio Games last month has come out firing at New Zealand, Australia and France, accusing them of poaching Pacific talent.
Ben Ryan led Fiji to their first ever medal at the Olympic Games.
Ryan told the BBC in an interview that he is worried about the development of rugby in the Pacific Islands, saying that nations such as New Zealand, Australia and France are luring players away with big cash offers.
"Anyone can do anything, so it's the Wild West in that respect," the former Fiji Sevens coach told the BBC.
Ryan, 45, is concerned with the lack of licensed agents and rules around bigger nations plucking players from the Pacific.
He believes it will be the downfall of Pacific rugby with players opting to play international rugby for New Zealand, Australia and France rather than their country of birth.
Fiji's Osea Kolinisau scores in the sevens final.
Source: Associated Press
"They get a Super Rugby contract dangled in front of them and they don't then come back across to play for Fiji," says Ryan.
"In 10 years' time, if things don't change, I see an Australian side with half their team coming from the islands, at least.
"There will be four or five others in France without doubt, because I know there are young kids there who are phenomenally talented and a year off getting residency, so it's inevitable unless we make something happen quickly."
After leading Fiji to victory over Great Britain 43-7 in the Olympic Games final, Ryan was given an honorary chief title and land.