Wales have been issued with an official warning by World Rugby following what the governing body has described "an apparent breach" of the World Cup terms of participation agreement regarding training arrangements.

Wales included a number of players from outside their 31-man World Cup squad during a training session in Surrey on Wednesday.

In its statement, World Rugby said: "The Wales team has been issued with an official warning following an apparent breach of the spirit of the Rugby World Cup 2015 terms of participation regarding team training arrangements, and specifically the inclusion of a number of players from outside the selected 31 player squad for a training session yesterday.

"Having reviewed the matter, World Rugby is satisfied that no deliberate breach was intended.

"And in addition to the formal warning to the Welsh team, all participating teams have been informed that additional players from the extended national team squad, including potential injury replacements, may not participate in any training sessions."

Earlier, World Rugby planned to seek clarification from the Wales set-up.

No formal investigation was launched by World Rugby.

Wales continued their preparations on Thursday at London Irish's new training facility in Sunbury ahead of Saturday's crunch Pool A clash against England at Twickenham.

There has so far been no official Welsh Rugby Union response to World Rugby's statement.