Police hope the beer bottle that put a 65-year-old woman in Tauranga Hospital intensive care will lead to an arrest.
Tauranga CIB head Detective Senior Sergeant Greg Turner said the bottle that hit Mary Loader in the face on Saturday, causing serious injuries, had been sent to Environmental Science and
Research for forensic examination.
"I remain hopeful that we might get a result towards the end of the next week, but ... we are pushing on with inquiries to find who may be responsible," he said.
Mrs Loader remains in a stable, but serious condition in hospital.
The bottle was thrown at her from a moving car containing about four young men as she walked along Domain Rd in suburban Papamoa at 8.20am on Saturday.
Her family said it was a senseless act which had left her almost unrecognisable.
Mrs Loader had surgery to put metal plates in her face and doctors put her into an induced coma to improve her chances of recovery.
Her daughter Vicky said her mother was in surgery for three hours as surgeons inserted five titanium plates to hold together her shattered face bones.
The impact of the bottle left a deep gash between her eyes, another between the nose and top lip, shattered cheekbones and a broken nose.
Vicky Loader doubted the four young people in the car realised what they had done.
It was "a mindless act that caused so much devastation", she said.
Mr Turner said earlier he hoped at least one of the car's occupants had a conscience and would contact police.
But help from the public was important in tracking down the vehicle.
- NZPA
