Wales attack coach Rob Howley has been sent home from the Rugby World Cup after he was alleged to have broken gambling guidelines.

The former Wales captain and scrum-half was in attendance at the squad's open training session in Kitakyushu on Monday, but absent from their capping ceremony later that day.

Wales Rugby Union released a statement this afternoon, saying Howley has returned home "to assist with an investigation in relation to a potential breach of World Rugby regulation 6, specifically betting on rugby union."

They added that the decision was taken "to act immediately in light of recent information passed to the WRU."

Stephen Jones has been drafted in to replace Howley in the Welsh backroom staff.

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 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. 

Wales will takes on Georgia in their World Cup opener on Monday.