Samoa's Trevor Leota is one of the big names who will be missing

Australian Rugby Union (ARU) chief John O'Neill says some clubs' "disgraceful" actions are preventing star players from smaller nations from playing in the World Cup, which starts in Australia on 10 October.

O'Neill has called on the International Rugby Board (IRB) to enforce its strict player availability rules if it was discovered that rich clubs were forcing players from smaller nations to put club before country.

"If you have regulations that govern the game off the field and they're not being complied with, then there's something wrong," said O'Neill.

"If it's a blatant disregard and blatant abuse of the regulations, which detract from the international game, then it is a disgrace."

I'd like the next World Cup to have 10 or 12 teams capable of winning Australian legend David Campese

At least five Pacific island players and four from Namibia have ruled themselves out of the World Cup in favour of playing for their club sides.

"We regard the World Cup as the pinnacle of rugby, so it's less than satisfactory if some of the world's best players, representing particularly smaller nations, aren't here because of a conflicting commitment to clubs," an ARU spokesman said.

IRB regulations say clubs can be fined, suspended or docked points if they stop players representing their country.

Meanwhile, former Wallaby great David Campese has backed the smaller countries, saying they need to be nurtured in order to make the World Cup more competitive.