Sydney - Rugby Australia chief Raelene Castle penned an apology to World Rugby over the behaviour of some members of the Wallabies entourage, led by coach Michael Cheika, at the Japan Rugby World Cup, a report said on Wednesday.
The Sydney Morning Herald said she fired off a letter saying sorry after concerns were raised by the local Japanese organising committee as well as high-ranking rugby officials.
They were believed to be related to Cheika's criticism of World Rugby and referees, and issues with Australian management during the team's time in Japan.
Rugby Australia confirmed to AFP "there was a letter", but said it would not be commenting further. "The issue is behind us," a spokesperson added.
Cheika, who quit at the end of the World Cup, was vocal after Fiji referred Reece Hodge for disciplinary action over a heavy tackle which left Peceli Yato concussed in their group game.
The Wallaby wing was subsequently suspended for three weeks.
"If there is one bloke World Rugby is not listening to it's me," Cheika said at the time of Hodge's suspension.
"No matter what language I spoke to them in.
"There is a bit of us versus everyone else. You know and we know that. So we are not going to let it derail us."
He also slammed the decision to penalise Samu Kerevi for a ball carry that floored Wales flyhalf Rhys Patchell, saying: "As a rugby player, a former player, I am embarrassed," while claiming referees were "spooked" by a crackdown on high-tackles.
The Herald suggested his attitude and overall "us-against-them" demeanour filtered down to other members of the Australian camp and Castle did her best to clear the air with her letter.
In a bombshell on his departure, Cheika revealed he barely had a relationship with the Rugby Australia hierarchy, led by Castle, apparently stemming from his powers being watered down by the appointment of Scott Johnson as director of rugby.
Cheika, whose contract was due to expire at the end of the year, fell on his sword after the Wallabies were sent packing in the quarter-finals by England.
New Zealander Dave Rennie was appointed as his replacement last week.