(Reuters) - Referee Craig Joubert wrongly awarded Australia's winning penalty in their 35-34 quarter-final defeat of Scotland at the Rugby World Cup but there is no plan to change the TMO system, organisers said.

Australia fly-half Bernard Foley converted the penalty on Sunday at Twickenham to send the Wallabies into a semi-final against Argentina to be played next weekend.

Distraught Scotland players and fans wondered why Joubert had not referred his decision to the television match official (TMO) but organisers World Rugby (WR) said on Monday that he had adhered to protocols.

However, while the referee had not been permitted to consult the TMO, World Rugby issued a statement saying Joubert had made a mistake in awarding the penalty for "deliberate offside" by Scotland's Jon Welsh at a lineout in the 78th minute.

TV replays immediately showed an Australian player had touched the ball, putting Welsh onside.

"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," WR said.

"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."