Australia coach Michael Cheika says authorities are "spooking" referees and that he was "embarrassed" by some decisions in the loss to Wales.

Wales moved top of World Cup Pool D with a 29-25 win in Tokyo on Sunday.

Cheika was angry at the decision to penalise Samu Kerevi when the centre was carrying the ball and noted booing from the crowd following the call.

"Administrators are spooking the refs and refs are afraid of making decisions," he said.

Referee Romain Poite referred the tackle to the television match official and Kerevi was judged to have led with his forearm into Rhys Patchell's chest then throat.

Former New Zealand fly-half Andrew Mehrtens said on BBC Radio 5 Live it was "opening a dangerous can of worms".

"If you slow it down, everything looks worse. It's dangerous ground and you're going to end up with a game with no contact at all," he added.

Wallabies captain Michael Hooper remonstrated with Poite and later said Wales fly-half Patchell had shown "poor tackle technique".

World Rugby introduced new rules in 2017 to "change culture in the sport to ensure that the head is a no-go area" and published a framework to help referees rule on high tackles in May.

The governing body criticised its own officials on Tuesday after Reece Hodge's collision with Peceli Yato during Australia's opening win over Fiji went unpunished.

Wallabies winger Hodge later received a three-match ban after being cited for the high tackle.

Cheika said: "When our player does it, we get suspended, and then this time we get penalised. As a former rugby player, I am embarrassed about it."

On the Kerevi incident, Cheika said: "He put his arm into his chest. I don't know if that is illegal or not. I don't know the rules any more, honestly.

"Everyone seems worried about stuff so much. I don't know why. The players aren't worried."

Asked if rugby was getting "softer", Cheika said: "You've got to take care, you've got to look after players, but not to an extreme where you're looking after players just for doctors and lawyers," he said.

"You've got to look after players for players."