Marcoussis - The head of world rugby on Thursday vowed a "strict application" of the rules on releasing players for international duty, amid claims that three Fijians were barred by their clubs from the 2011 World Cup.
The chairperson of the International Rugby Board (IRB), Bernard Lapasset, said the main northern hemisphere federations were due to meet this month and they would get to the bottom of the issue.
"We'll see if we have to change the rule. If we have to start investigations, we'll do so. It'll be with complete transparency and in the strict application of the rules," he said at the national centre for French rugby in Marcoussis, near Paris.
Rugby's financially poorer countries, particularly the Pacific Islands, have long alleged that they face economic "blackmail" by wealthy clubs in the sport's more established nations.
Under IRB rules, clubs must release players at times designated for full internationals, such as the upcoming November international "window", and for major tournaments including the World Cup.
But clubs have tried to get round this by agreeing clauses in contracts with players from cash-strapped Pacific Island nations, who then make themselves unavailable for Test duty, as happened at last year's World Cup in New Zealand.
The former backs coach of French Top 14 side Racing-Metro, New Zealander Simon Mannix, on Wednesday claimed in British newspaper The Independent that his former club had paid three Fijians not to take part in the 2011 World Cup.
Racing has not responded to AFP about the allegations but denied the accusations in the daily.
IRB regulation nine forbids clubs from offering disincentives, either through "contract or conduct", to players to represent their country but critics maintain that officials have not done enough to enforce the rule.
The IRB said in a statement from its Dublin headquarters on Wednesday that it would act on breaches of the regulation, calling player release "central to the integrity and economic sustainability of the international game".
"The regulation is designed to deliver a fair, equitable and proportionate framework for facilitating the release of the world's best players for international duty within designated windows without impediment irrespective of country of employment," it added, warning it took any breach "very seriously".
"Unions also have a clear obligation to do everything possible to uphold the regulation within their territory or they risk significant sanctions," the statement concluded.
Lapasset said on Thursday that those sanctions "could go all the way to expulsion" but that it was unfair to single out French clubs when the rumours of the practice had been around for a number of years and at previous World Cups.
"The rule provides for the release of players for competitions strictly organised in a calendar. We strive to compose a playing calendar which works despite the odd doubling up of competitions here and there," he added.
"In France, there's a club competition at the same time as international competitions. We try our best to have the best players against the best players, the best teams against the best teams".