Australia assistant coach Scott Wisemantel has resigned from his position just eight months out from the 2023 Rugby World Cup.
Wisemantel returned to Australia's coaching set up in December 2019 after spending 18 months in a similar role with England.
In a big blow for the Wallabies ahead of the World Cup in France, they are now seeking a new right-hand man for head coach Dave Rennie.
Wisemantel confirmed in a statement on Rugby Australia's official website on Thursday that the decision was down to personal reasons.
"While this has been a very difficult decision, it's one that's best for me and my family at this point in time," he said.
"The World Cup is the pinnacle of our sport and requires 100-per-cent commitment and that's something I'm unfortunately unable to give at the moment.
"I've loved being with this team under Dave and wish them all the best for their season and in the World Cup later this year."
Wisemantel boasts 20 years of coaching experience and has worked as an assistant at the past four World Cups with Australia, Samoa, Japan and 2019 finalists England.
Australia boss Rennie is disappointed to have lost a key member of his staff but understands the decision.
"Scott's a top man and one of the best coaches I've ever worked with," Rennie said.
"He's hugely respected around the world, has a mountain of experience at International level and an incredible rapport with our players.
"While we did all we could to try and keep Scott, we respect his decision and wish him, Gabs and the girls all the best.
"He's been a massive part of this group for the past three years and we'll miss him."
Australia concluded their 2022 campaign with three defeats from their five November internationals, having also finished third in the Rugby Championship.
The Wallabies will face Wales, Fiji, Georgia and Portugal in the pool phase of the 2023 Rugby World Cup, which gets under way on September 8.