An investigation is underway into a teenager's allegation she was assaulted by police during a wild teenage party in Auckland.

Pictures of a bloodied Ella Ekatone, 15, have been posted on Facebook by friends who attended an 18th birthday party on Wellington St on Saturday.

The party got out-of-control with reports of people passed out in the streets and when police arrived they were pelted with dozens of bottles.

About 35 officers tried moved to disperse about 150 party-goers and were responding to a 111 call from the property where the party was being held.


Her friend Anna Gardiner said the Howick College student was leaving the property as directed by police when she was shoved to the ground multiple times.

"What gives police the right to do this to an innocent teenage girl? Yes teenagers playup and get out of control at parties, we all know this but what gives the cops the right to enforce such violent actions on someone that wasn't doing anything wrong,'' she wrote online.

Counties Manukau Police District Commander, Superintendent John Tims confirmed an investigation was underway.

"The female alleges to have been pushed by police.

"Police were called to the address at around 11.15pm, we were advised that there were individuals intoxicated and passed out on grass verges. One police unit completed a drive-by to carry out an assessment of the party. Whilst doing this they observed around 150 people on Wellington Street and around 50 bottles were thrown at the police patrol car.''

Mr Tims said: "Police officers in the patrol vehicle then called for back up...The officers moved in to the address and tried to disperse the partygoers from the house and also the surrounding areas. No one was arrested as a result of the house being cleared of party goers.''

It's understood some arrests occurred nearby when a fight broke out but it was unclear if they had been to the party or not. The complaint was now being investigated by the Independent Police Conduct Authority.

"We are speaking to witnesses and also all the police officers that were present at the Wellington Street event to ascertain exactly what happened.''