All Blacks flanker Jerome Kaino has returned to New Zealand ahead of the Rugby Championship Test against Australia in Sydney on Saturday to deal with a "personal matter".

New Zealand Rugby (NZR) confirmed in a statement that Kaino had returned home after the Daily Telegraph newspaper in Sydney claimed Kaino was having an affair with a 24-year-old Canberra model.

Kaino, 34, a double World Cup winning All Black, was a surprise omission from the match-day 23 when the New Zealand Test team was named on Thursday.

NZR said it could not comment on the allegations about Kaino nor new details which have emerged this week about scrum-half Aaron Smith's tryst in an airport bathroom last year.

"NZR cannot comment at this stage on what are both personal matters, but we feel for all of those affected," chief executive Steve Tew said.

"We certainly understand that our game and our players are under public scrutiny and these latest stories are concerning.

"We take these issues very seriously, and are also mindful that these issues affect people with families and loved ones."

The New Zealand Herald reported on Saturday there were with fresh revelations suggesting the All Blacks management knew Smith's behaviour was not a one-off.

NZR announced this week that it is reopening an investigation into the original sex scandal, after a claim by the woman involved that Smith offered her money to sign an affidavit which would have falsely claimed they did not have sex in the airport toilet.

source: AFP