"We've got a lot of information together which we're not making public in respect of the injuries she's sustained or how she possibly sustained them.
"She remains in a critical condition in Palmerston North Hospital. Her injuries are life threatening.
"We haven't been able to speak with her, which obviously makes it difficult,'' Mr Sheridan said.
"It's a confined investigation and we're just working closely with her family, friends and neighbours.
"Everyone that we've wanted to speak to we've been able to speak to which is great.''
The `"substantial'' injuries were not self-inflicted and no one had yet been taken into custody, Mr Sheridan said.
"Our aim is to determine how the injuries were inflicted and who was responsible for them.
"The fact that she's in such a bad way and our inability to speak with her doesn't make it easy.
"At the moment as far as she is concerned, we are just closely monitoring the situation on an hourly basis. At the same time, we're not sitting on our hands, we're conducting a scene investigation and we're still there, that takes days.
"One of the purposes of that is to help piece together what might have happened.''
At the same time the woman sustained her injuries, firefighters battled a blaze five houses from her apartment.
That fire was not thought to be deliberately started, but local resident Rosie Walker said the blaze caused so much commotion, no one would have heard the woman screaming.
Mr Sheridan said there was no link between the fire and the woman sustaining her injuries.
Up to 18 officers were working on the investigation, as well as two forensic staff from Environmental Science and Research.
