A 21-year-old student is in Dunedin hospital after being beaten unconscious by an intruder at her family home on Wednesday afternoon.
The young woman phoned her mother, saying she was concerned about strange noises in the house, in Scobie Rd in the suburb of Waverley.
On hurrying home from work, the mother found her daughter unconscious with a head injury. A weapon was lying nearby.
The police won't reveal what sort of weapon was found but hope it will provide clues to the attacker's identity.
Detective Senior Sergeant Steve McGregor says the attack could have been a burglary gone wrong, or something more sinister: the police are keeping an open mind at this stage.
He says it's unclear how the intruder entered the house or whether anything was stolen, and the victim has been unable so far to give a full account of the attack because of her head injury.
The police would like to hear from anyone who saw suspicious behaviour in Scobie Rd between 1.45pm and 2.15pm on Wednesday.
A team of 20 officers is working on the case.