Rugby union's world governing body's confirmed Australia's match-winning penalty in yesterday's World Cup quarter final with Scotland should not have been awarded.
In a statement, World Cup says referee Craig Joubert should only have given the Wallabies a 78th minute scrum, not a chance to kick at goal.
The controversial decision enabled Australia to progress to the semi-finals with a 35-34 win, meaning no Northern Hemisphere teams progressed to the final four.
In the statement, World Rugby said: "On review of all available angles, it is clear that after the knock-on, the ball was touched by Australia’s Nick Phipps and Law 11.3(c) states that a player can be put on-side by an opponent who intentionally plays the ball.
"It is important to clarify that, under the protocols, the referee could not refer to the television match official in this case and therefore had to rely on what he saw in real time. In this case, Law 11.3(c) should have been applied, putting Welsh onside. The appropriate decision, therefore, should have been a scrum to Australia for the original knock-on."
