Dunedin police are still on the hunt for a man who sexually assaulted a female runner on Monday night.
The 23-year-old woman was knocked to the ground, tied up and assaulted about 9.15pm, in what police have called a "random" attack at Ross Creek reservoir, just off the main track.
A police spokesman said the perpetrator was still on the run today.
The attacker is described as European, tall and of a skinny build. He was thought to have been wearing black shoes, a black T-shirt, and a pair of black Skins leggings with white writing.
The attack ended when the man was surprised by a pale-coloured dog, possibly a labrador, and fled the scene.
The woman managed to free herself, but was initially too scared to leave the area in case the attacker was still there.
Detective Senior Sergeant Kallum Croudis told media yesterday that the public should be vigilant and report any suspicious activity.
Such crimes were rare in Dunedin, he said.
Scientists from the Institute of Environmental Science and Research had been called in to help examine the scene this afternoon.
Police said they had spoken to the owner of a light-coloured dog, but wanted to talk with anyone else who was walking a similar-coloured dog in the area about 9pm.
They urged anyone who was near Ross Creek at the time, or who saw a man matching the description, to come forward.
A team of more than 20 detectives and uniformed staff was involved in the operation and the area would remain cordoned off today.
Anyone with information can call the Dunedin central police station on (03) 471 4800 or anonymously via Crimestoppers on 0800 555 111.