Eddie Jones has been working with New Zealand star Beauden Barrett as part of the England head coach's consultancy role with Japanese side Suntory Sungoliath.

Jones has an association with the Tokyo-based team spanning over two decades and continues to offer guidance to their coaches and players, including two-time world player of the year Barrett.

It is Barrett's debut season in the Top League and while he has praised Jones' input, the Australian's presence in Japan is controversial as it comes in the wake of England's fifth-place finish in the Six Nations.

A Rugby Football Union review of the championship offered Jones its full backing and declined to criticise the head coach, who is contracted until the next World Cup in January 2023.

"Eddie has had a little bit to do with Suntory rugby and he's been so good for me with my dealings with him," said Barrett, one of the game's biggest stars who has won 88 caps for the All Blacks.

"When he does have something to tell me, they are like little pieces of gold. His understanding of the game is exceptional. He's been involved a fair bit, certainly at the start of the season.

"He's over here at the moment, actually. He's more in the background and dealing with the coaches a lot, but when he does offer advice to the players, it's certainly good advice.

"It's good to get that from someone who isn't there on a daily basis. He's on the outside looking in and gives good information."

Jones is using annual leave for his trip to Japan and the RFU has sanctioned his work for Suntory.

"Eddie has had a consultancy agreement with Suntory for over 20 years. We have been aware and comfortable with that since he joined the RFU," an RFU statement read.

"He provides consultancy in his holidays and this role is in no way a conflict with his England team priorities."