A crowd of 15,000 nestled in the Gibbston hills at a previous concert. Photos: ODT
Sergeant Simon Matheson said the complainants had bought tickets on online platforms, only for the sellers to then block their identity and not hand over the tickets.
He said the sellers had assumed other people's identities.
He advised people wanting to buy tickets from people advertising online to be "very wary and do everything you can to confirm the identity of the seller and that they actually hold possession of the lawful ticket".
Ideally, the would-be buyer would have a face-to-face meeting with the seller, he said.
Sgt Matheson said police would welcome hearing from anyone else who has been defrauded.
Artists for Saturday's concert include Billy Idol, Anastacia, Creedence Clearwater Revisited and George Thorogood and The Destroyers.
