Johns sex inquiry won't be reopened: NZ Police

The investigation into the sex scandal that cost disgraced rugby league personality Matthew Johns his job will not be reopened, New Zealand police say.

Johns' media and coaching career is in tatters after the ABC's Four Corners program aired allegations about his involvement in a 2002 group sex incident in Christchurch while he was playing for Cronulla.

Johns was one of several Cronulla players who took part in the act with a 19-year-old woman.

At the time, New Zealand police investigated the woman's claims that the sex was non-consensual, but the investigation cleared all players of wrongdoing.

Detective Inspector David Long, from Christchurch police, said the original investigation involved up to 80 interviews, and was thorough and conclusive.

"I'm completely satisfied that we got full and truthful accounts at the time and that no crime was committed," Mr Long told AAP on Thursday.

"There's renewed interest now, obviously from this television programme, but there's been no new information whatsoever that's come forward that changes anything.

"So as far as reopening it, it's just not going to happen."

He said the moral issues around group sex with a teenager were best left to commentators and were not a matter for police.

"There are moral aspects to this ... but these are not for the police to consider when enforcing the law," Mr Long said.

He also said the woman involved had been in touch with him again recently regarding the case, but that contact had not altered the situation.

Johns has been stood down by the Nine Network and has quit his position as an assistant coach at the Melbourne Storm in light of the recent developments.

On Wednesday night, the former Test star apologised for the "pain and embarrassment" he caused the woman, but insisted she was a "willing participant" in everything that occurred in the hotel room seven years ago.

"Any trauma and embarrassment she has gone through as the result of this incident I am extremely sorry for," Johns told the Nine Network.

"At no point did she object to what was going on ... at no stage was she under any distress."

He said he was not guilty of abuse, but he was guilty of infidelity and stupidity.

- AAP