Raelene Castle left visibly upset after face-to-face Tokyo tear-up with Cheika - report

Rugby Australia boss Raelene Castle was left visibly upset after a face-to-face Tokyo tear-up with Wallabies head coach Michael Cheika - according to reports.

The report from the Sydney Morning Herald comes as Cheika made a heartfelt apology to Australian rugby fans amid speculation his next move is to France.

Cheika's tumultuous five years in the Australian role ended with the Wallabies' disappointing World Cup quarter-final exit in Japan last weekend.

Amongst a brutal post-mortem it's been reported that the coach and Rugby Australia boss Raelene Castle got into a heated clash at an embassy reception in Tokyo during the tournament, which left Castle visibly upset.

Castle and Cheika were in Tokyo at a function following the Wallabies' first game with Fiji. Castle had requested that Cheika send Wallabies players to the reception at the Australian Embassy, but the 52-year-old resisted the request for players with the team set to play Wales in the most important match of the Pool stages for the men in green and gold.

Wallabies DoR Scott Johnson was then tasked with getting a handful of Wallabies to attend, which he did. When Cheika found out that Castle had effectively gone over his head, a row erupted at the embassy.

The Sydney Morning Herald report that former Wallaby Morgan Turinui had to step in to separate the pair.

The pair have admitted they had barely spoken this year such was the fraught state of their working relationship.

Cheika has been freshly linked with Top 14 side Montpellier as their director of rugby.

Cheika didn't address his employers or the incident but thanked Australian fans for their loyalty in an open letter on the Athletes Voice website released on Wednesday.

He apologised to fans for their disappointing World Cup performance.

"I want to personally thank you all and also say that I am truly sorry we could not go one better in this World Cup than we did in 2015," Cheika wrote.

"As the head coach of the Wallabies I want you to know that I feel that weight of carrying all of your hopes and I love the responsibility that comes with it.

"That is why I made the call a while back that if we didn't win this World Cup I wouldn't ask to be reappointed, even though I would have loved to continue coaching our national team."

He also thanked his players, saying they had shown mettle to bounce back "despite the many obstacles that have been put in front of you over the last few years".

Cheika made particular mention of forwards Izack Rodda and Lukhan Salakaia-Loto, who both lost a parent while part of his squad.

"We wanted to try to share your pain and walk with you along the way and it's inspiring to see the way you have both stepped up for your families.

"Having l ost my own father nearly 18 years ago now, I feel for you and I know your dads would be immensely proud of the men you are becoming."

Cheika also paid tribute to Wallabies veterans David Pocock, Christian Lealiifano and Will Genia, among others who have likely played their last Test match.

Those players are shifting their careers overseas and it appears Cheika is set to do the same with French rugby newspaper Midi Olympique reporting Cheika may replace Kiwi Vern Cotter when his contract ends in June.

French-speaking Cheika played in France for four years during his 20s, coached Paris powerhouse Stade Francais between 2010–2012, plus his four children are bilingual.

At Montpellier, Cheika would coincidentally be a part of the same organisational structure which he said was behind his fallout with Castle and chairman Cameron Clyne.

Cheika would oversee head coach Xavier Garbajosa as Scott Johnson did over him in the Wallabies set-up.

The paper said that the recruitment of Cheika by the club's billionaire president Mohed Altrad, would help attracting players.

It added that despite his lack of success with Stade Francais and most recently with the Wallabies, his "overall track record remains impressive".

- AAP, additional reporting RugbyPass