The World Rugby match official selection committee has confirmed the controversial decision made by referee Craig Joubert in Sunday's quarter-final was wrong.

Following a full review of the penalty that enabled flyhalf Bernard Foley to secure a one-point win for the Wallabies over Scotland at Twickenham, World Rugby clarified that a scrum should have been awarded instead.

'The selection committee confirms that Joubert applied World Rugby Law 11.7 penalising Scotland’s Jon Welsh, who had played the ball following a knock-on by a teammate, resulting in an offside,' a statement released late on Monday read.

'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 onside by an opponent who intentionally plays the ball.

'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.'

While confirming Joubert's mistake, World Rugby high-performance match official manager Joël Jutge came out in defence of the South African referee.

'Despite this experience, Craig has been and remains a world-class referee and an important member of our team.'