Former Racing Métro backs coach Simon Mannix has alleged that Fijians at the Parisian club were paid to be unavailable for the 2011 World Cup so they could play in the Top 14 instead.
Clubs are required to release players during international windows and for major tournaments such as the World Cup and IRB Regulation 9 forbids clubs from offering players incentives, either through "contract or conduct", to turn down a national call-up.
Former All Black fly-half and current Munster backs coach Mannix, who was part of the Racing staff from 2006 until he was fired last November, has accused the big-spending French club of using its deep pockets to keep some players in Paris last year.
"Racing Métro had Fijians who declined to go to the World Cup ... because the club gave them a cheque if they stayed here [in Paris]," Mannix told The Independent.
Sireli Bobo and Jone Qovu cited "personal reasons" while Josh Matavesi (now at Worcester) said he wanted to focus on club commitments when they declined to play for Fiji in the 2011 Pacific Nations Cup, effectively ruling themselves out of World Cup selection.
The Racing Métro President Jacky Lorenzetti has denied the club made any illegal payments or broke any regulations.
"(The accusations) make me laugh, especially coming from Simon Mannix. Nothing else to add," Lorenzetti told French site Rugbyrama.
Northampton lock Samu Manoa chose to play in the Premiership rather than with the USA Eagles at the 2011 World Cup although Saints insist it was the player's personal choice.
The 2015 World Cup will once again overlap with European domestic leagues and the tournament risks being devalued should players from cash-strapped teams like Fiji, Tonga and Samoa be persuaded to rather feature for their clubs.
While critics suggest the IRB have not done enough to enforce Regulation 9 the global governing body insists it can only take action if it receives a complaint.
"The IRB can only act on player release issues if requested to do so by a union or if it is provided with credible evidence that would allow it to pursue its own enquiry," read an IRB statement.
Former Fiji Fly-half Nicky Little, who has played for clubs in five European countries, said the practice was not new.
"For many seasons, European and UK-based Islanders have either been blackmailed not to play for their countries, or had pay docked when they were with their national teams," Little, who represented Fiji in four World Cups, told The Independent.
Chief executive of the International Rugby Players' Association told the newspaper that the World Cup would be worse off if the practise was allowed to continue.
"We have been made aware of various situations where this kind of thing has happened but the players concerned haven't wanted to take it to the next level," said Nichol.
"If clubs can circumnavigate regulation nine, they will - and international rugby is the worse for it."