Wales assistant coach Rob Howley has been sent home from the Rugby World Cup in Japan following a potential breach of betting rules.
The former Wales international and attack coach was forced to leave the Wales camp in Kitakyushu amid the allegations of betting infringements.
The news comes just six days before Wales' opening World Cup game against Georgia.
The WRU confirmed he has returned to Wales to assist with an investigation "in relation to a potential breach of World Rugby regulation 6, specifically betting on rugby union."
A spokesperson said, "The decision was taken to act immediately in light of recent information passed to the WRU. No further details can be provided at this stage as this would prejudice the investigation. If required an independent panel will be appointed to hear the case."
The regulation in the World Rugby guidelines state that "no connected person shall, directly or indirectly, bet and/or attempt to bet on the outcome or any aspect of any connected event".
The WRU said he has "co-operated fully" with initial discussions. It added Warren Gatland has consulted with senior players and Stephen Jones will be arriving in Japan imminently to link up with the squad as attack coach.
Howley enjoyed a glittering playing career, winning 59 caps for Wales and captaining his country on 22 occasions, while also helping Wasps to be crowned European champions in 2004.
He become assistant coach January 2008 and while working as the backs coach at Cardiff Blues. He joined the national team on a full time basis in July 2008.
He also played for the British and Irish Lions in 1997 and 2001, and was part of the Lions coaching staff on their last three tours.
He had been due to leave his Wales coaching role after the World Cup, along with Gatland and fellow assistants Shaun Edwards and Robin McBryde.
Howley was recently linked with succeeding Conor O'Shea as Italy head coach following the tournament.