All Blacks great Sonny Bill Williams launched a stinging attack on Eddie Jones on Thursday, calling him "a disgrace" who "obviously lied" to the Australian players and fans.
Jones was appointed Japan's head coach on Wednesday, six weeks after the Australian quit the Wallabies following their dismal showing at the Rugby World Cup.
The 63-year-old had repeatedly denied being linked with the job and two-time World Cup winner Williams, now a pundit, said: "It's quite sad, isn't it?
"My thoughts on this whole saga is that he lied," Williams, who also played rugby league and had a successful boxing career, told Australian broadcaster Channel Nine.
"Obviously he lied to the players, he lied to the public, he lied to the Australian rugby union.
"What a disgrace."
During his time with the Wallabies Jones won two of nine tests, including a worst-ever World Cup where they failed to make it out of the pool phase.
He took the reins in January after being fired by England.
"Second point would be, I feel sorry for Japan. His track record speaks for itself," added Williams.
Jones, who will officially take over on January 1, previously coached Japan for three years from 2012 and is well respected there.
Nikkan Sports on Thursday said in a commentary it was clear that Jones was always going to get the job and hit out at the lack of "transparency".
"There are also doubts regarding the fairness of the process," it added.
"Some of the people involved have said it felt like a rigged race."