Mr Smith said police still needed to speak to anyone who was in or near Kuirau Park between 2am and 3am on Thursday, especially if they saw or heard anything suspicious.
Mr Smith said attacks of this nature were "thankfully incredibly rare".
"It is important when they do occur that the whole community pulls together with the police to identify the offenders as quickly as possible," he said. "The police will continue to carry out regular patrols of the CBD and Kuirau Park. We are also working with Rotorua District Council to use environmental design principles to improve safety for all of our residents and visitors."
Anyone with information should contact Rotorua police on (07) 348 0099. Information can also be provided anonymously via Crimestoppers on 0800 555111.