Kurtley Beale's Test career is in the hands of the ARU's integrity unit after the troubled playmaker was dropped for Saturday's clash with Argentina following a verbal altercation with a member of the Wallabies' management staff.

Beale faces an anxious wait as his employers investigate "an alleged incident" on the Wallabies' flight from Johannesburg to South America on Sunday.

Coach Ewen McKenzie said the full facts must be known before casting judgment after the staff member opted to return to Australia on Wednesday, while Beale remained with the Wallabies for their Rugby Championship closer in Mendoza.

But after declaring Beale available for selection, McKenzie axed the backline ace after a poor showing off the bench in last Saturday's 28-10 loss to the Springboks in Cape Town - and now this.

After opening the Rugby Championship as the first-choice five-eighth, the one-time world player-of-the-year nominee had been an impact reserve for the Wallabies' past three Tests.

Now he's out of the match-day 23 altogether and is at the mercy of an integrity unit headed by former long-time Wallabies team manager and policeman Phil Thomson and includes members of the ARU's human resources department.

While one more strike could mean out for the soon to be off contract Beale, just as it did precisely a year ago for his good mate James O'Connor, McKenzie said the 25-year-old was innocent until proven guilty.

"We've referred it to the experts," he said.

An ARU spokesperson said they expected the investigation to be completed by the end of next week.

Beale's 47-Test career has been dogged by off-field indiscretions.

Last year, he was sent home from South Africa after a scuffle with Melbourne Rebels teammates Cooper Vuna and Gareth Delve before being suspended then undergoing counselling and rehabilitation for alcohol-related issues.

McKenzie declined to divulge whether alcohol was involved in the latest incident but said he was determined to get to the bottom of exactly what happened.

The Wallabies' behavioural standards dipped when Robbie Deans was coach and only this week McKenzie's predecessor defended claims he'd been too lenient on O'Connor, Beale and Quade Cooper after they repeatedly landed in hot water. AAP