The Australian Rugby Union has clamped down on one of the Wallabies' party boys when they slapped utility back James O'Connor with a ban, ruling him out of the Tri-Nations decider against New Zealand in Brisbane on Saturday.

In a statement on Monday the ARU revealed that O'Connor has been suspended until August 28, for failing to attend the Wallabies' official World Cup announcement and photo shoot last Thursday.

The 21-year-old O'Connor was asked to provide the Sydney-based governing body with an explanation as to his non-attendance.

"A response was received earlier today [Monday] and considered, after which a decision was taken to suspend and fine O'Connor for his indiscretion,” the ARU said in the statement.

O'Connor was also given a suspended fine of AU,000 (US,425), which will remain in place until December 31, the ARU added.

He will now miss Australia's Tri-Nations decider against New Zealand in Brisbane on Saturday.

The talented young player , who was allegedly spotted at two popular Sydney bars last Wednesday night, issued a private apology to his teammates on Sunday - before fronting the media to express his remorse.

But his contrition was not enough to avoid missing out on the biggest match of his 30-Test career, with the Wallabies looking to claim their first Tri-Nations title since 2001 ... should they defeat the All Blacks at Suncorp Stadium.

O'Connor's absence is a major blow for the Wallabies given the in-from right wing is also the side's first-choice goal kicker.

Quade Cooper is likely to assume the kicking duties, while it is unclear how Deans will reshuffle his backline.