Key Points:

A group of friends who came to the rescue of a policewoman being beaten by a naked teenager, initially thought she was being raped.

The trio heard the officer screaming and crying for help in a reserve off Pandora Place, Pakuranga, on Monday afternoon.

One of the group, who did not want to be identified, said it wasn't initially obvious that the woman was a police officer. All they could see was a naked man bent over a screaming woman, leading them to think she was being raped.

As they got closer they saw the woman was actually being punched in the face. The witness said the teen hit the policewoman about 60 times.

"She had her arms up, trying to deflect his punches and protect her face."

While one of the friends rang 111, another ran towards the woman and yelled at the teen. "He wasn't phased, he just kept belting her. I suppose he was in panic mode.

"It was just a torrent of punches, it was unbelievable."

When the group member got close, the teen ran off.

"He made a mess of her. When she did get to her feet her face was all [covered in] blood. She was staggering and falling."

Police, who had heard their injured colleague's screams over the radio but didn't know exactly where she was until the witness called 111, were on the scene about a minute later.

The policewoman, who suffered scratching to the cornea of her eyes and substantial bruising, and her partner had turned up to the teen's house after he allegedly robbed a dairy twice in six minutes. The teen, who had been in the shower, ran off wearing only a towel.

He was chased by the officers, who split up as they ran. When the policewoman tried to stop him he allegedly started attacking her.

The witness said the policewoman, who is believed to have only been in the job a few months, was incredibly brave and hoped the severe beating wouldn't deter her from pursuing a long career with the police.

"She's got balls, she's got the makings of a bloody fine officer."

The policewoman was discharged from hospital and was yesterday visited at home by Police Commissioner Howard Broad. She is not expected to suffer any permanent injury. One of the police officers who came to the policewoman's aid was stung by bees.

A 16-year-old has been charged with aggravated wounding, aggravated robbery, and two counts of assault on a police officer in relation to the attack.