Police are hunting a five-foot-tall man with a dog who allegedly sexually violated a teenage girl at the Occupy Christchurch site in Hagley Park.
Detective Sergeant Darryl Sweeney said the assault happened mid-afternoon yesterday, with police called in the evening.
He said officers were carrying out a scene examination at the site and protesters were cooperating with the investigation.
The offender was described as a male caucasian who is about 1.52m, or five foot, tall with pale skin, short brown hair and blue eyes.
He was believed to have had a brown Staffordshire bull terrier with him.