Police are investigating allegations that a group of league players played a part in throwing a bottle into a window that shattered and caused injury to a woman.
However, the team of those accused - the Point Chevalier Pirates - says the allegations are baseless and "underhand tactics" from their opponents - the Mt Albert Lions - ahead of the grade final today.
Pirates chairman Glenn Poole said his players had left the party when the incident allegedly took place last month.
He said the allegations were coming from within the Mt Albert Lions club and their supporters - who they were due to face off against in the Fox Memorial Cup final match.
An Auckland City police spokeswoman confirmed that officers were "investigating an incident at a party in Auckland". She could not give any further detail.
Photos and commentary about the woman's injuries - allegedly sustained after a bottle was thrown into a window, shattering it and spraying glass into her face - were posted to Facebook accusing members of the Pirates of doing the damage.
Mr Poole said the allegations were "social media nonsense" and that players were considering legal action under the Harmful Digital Communications Act.
"It is completely unfounded. There is no substance and there is nothing to the allegations," he said.
"People [use] some underhanded tactics to try and put people off the game and it's pretty nasty."
Mt Albert Lions manager Bill Werry said there was a lot of rumour and gossip surrounding the incident, but welcomed the outcome of the police investigation.
"I have seen the photo and if [the accused] goes through the New Zealand police and the justice system I am sure justice will served. If not, I feel for [the accused] if he has been falsely accused."
Auckland Rugby League chief executive John Ackland said he would not comment on the matter if it was under police investigation.
NZ Rugby League spokesman Grant Chapman said there was no obligation for the club to report the incident to them.
"Our jurisdiction is mainly around on-field or sideline incidents, and we are guided by the legal system on incidents such as this."