Detective Sergeant Brian Cameron was appealing to anyone who may have witnessed suspicious activity near the Mackinnon Tce and Fernhill Rd intersection, between 1.30am and 2.45am yesterday.
''It's possible that he followed her as she walked along Fernhill Rd between Sainsbury Rd and Mackinnon Tce,'' Det Sgt Cameron said.
It was likely the intruder, who was unknown to the victim, entered the house through the unsecured front door, before going into the victim's bedroom and sexually violating her.
Her ringing phone had spooked the intruder, who then escaped the house, climbing out a bathroom window, he said.
''It's very fortunate for the victim that the attacker has been scared off,'' Det Sgt Cameron said.
The victim had undergone a medical examination, did not suffer any injuries in the attack, and was now being supported by her partner, he said.
He asked the Fernhill community to help find the person responsible as quickly as possible to avoid any further attacks.
The attacker was described as a dark-skinned male of average height, with athletic build and wearing a grey hooded sweatshirt, speaking with a non-Kiwi accent.
Det Sgt Cameron urged people to check and lock doors and windows before going to bed and if possible, install an alarm inside and sensor lighting outside homes.
Queenstown police (03) 441-1600, Crimestoppers, 0800 555 111.
