The then 48-year-old former Wales captain had been a part of Warren Gatland’s coaching team since 2008 and left Wales’ World Cup squad base in the southern Japanese city of Kitakyushu while an investigation into his betting activities took place.
The Welsh Rugby Union said at the time that Howley had “returned to Wales to assist with an investigation in relation to a potential breach of World Rugby regulation 6, specifically betting on rugby union”.
Howley was sent home six days before Wales’ opening World Cup game against Georgia, a fixture they went on to win 43-14.
In a statement, the WRU said: “The WRU can confirm that Rob Howley 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.
“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.
“Rob has co-operated fully with our initial discussions, and we would ask that the media appreciate this is a difficult and personal matter for Rob and that his privacy is respected before an outcome is reached.
“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.”
Following the investigation, Howley was banned from all involvement in rugby for 18 months, nine of which were suspended, with the ban being backdated from the date he returned home from the tournament.
It emerged that Howley was charged with making 364 bets on rugby union over a four-year period, with 24 on games connected to Wales including two upon Wales players scoring tries.
Howley placed a bet on a Wales player to be the first try-scorer in the 25-7 Six Nations victory over Ireland in March 2019, but Howley stated that it was part of a treble bet, adding that it was a part of his normal recreational betting activity.
However, he later admitted that he knew he could not bet on matches involving Wales and that it was a breach of World Rugby anti-corruption and betting regulations.
Following examination of Howley’s electronic devices, including his laptop and phone, “no material was discovered which incriminated Mr Howley to an extent greater than that which he had already admitted”.
Wales reached the semi-finals of the 2019 World Cup before losing 19-16 to eventual champions South Africa.