Former Wellington rugby player Losi Filipo was discharged without conviction for an assault committed when he was 17-years-old.

New Zealand rugby personality Sir John Kirwan has apologised to the assault victims of Losi Filipo, saying it was the sport's responsibility to look after its young players.

Kirwan made the apology on behalf of the rugby community on Breakfast on Thursday, saying he thought NZ Rugby was now coming good on its promise to speak with the victims of the October 2015 Wellington attack.

"I'd like on behalf of all rugby people to apologise to all the victims personally. What's happened is terrible," Kirwan said.

The former All Black and Blues coach also commented the Filipo incident had highlighted a "wider issue" of under-age drinking, with the now former Wellington player causing the trouble on a boozy night out.

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Kirwan said he believed NZ Rugby was now taking up appropriate responsibility for the Filipo incident.

"What's happened has been horrible for the game and we need to stand up and take responsibility for that, however late," he said.

Filipo lost his playing contract with the Wellington Rugby Union after an intense day of public scrutiny following a judge's decision to discharge him without conviction for the attack on four people, including two women.