New Zealand star Tana Umaga has been reprimanded by the All Blacks management following his part in a drunken late-night clash last weekend.

The burly winger was caught on video being helped back to his hotel room by team minders after a night out celebrating New Zealand's 25-12 Tri-nations victory over South Africa.

Umaga has been reprimanded over the incident, which took place in central Christchurch in the early hours of Sunday morning.

Witnesses have said Umaga had attempted to pick a fight with well-wishers, but other bystanders said he had been blameless in the incident.

All Blacks manager Andrew Martin said Umaga had been drunk, and described the player's behaviour as "unacceptable."

"It's not appropriate behaviour and we don't deny that," he said. "Tana himself is most remorseful and has expressed his disappointment to me personally," he told local television here. "That is not how our All Blacks conduct themselves in public."

Jason Parker, who caught the incident on a home video camera, said Umaga had sworn at well-wishers and was spoiling for a fight.

But another bystander defended the player. "Umaga had been drinking but was just having a good time and had stopped to talk to people," Angela Watkin said. "There was a guy trying to pick a fight and Umaga was trying to walk away."

Martin said All Blacks needed to be aware of their responsibilities as role models.

"We all expect New Zealand men to go out and have a beer on the Saturday night after a game of football, and All Blacks are no different in that regard. But we have public responsibilities as All Blacks and role models," he said.

"From that point of view it is quite unacceptable for an All Black to get as drunk as that in public."