Detectives are calling for witnesses who may have seen a teenage girl at the event, who may have been in the company of a group of boys aged between 18 and 20.

The teenage girl was wearing a fluro-orange crop top with thin straps, navy blue flared pants with a flora pattern and Doc Martens boots.

She is about 172cms tall, has brown hair with a fringe and blonde highlights.

The girl was also carrying a Nike bag and wearing prescription Ray Bans.

Tasmania Police are investigating the fact the girl may have been in the company of the group of boys between 8-10pm.

One of the boys is described as wearing a dark-coloured felt hat and a white shirt with green or black stripes.

If you remember this group of people, or think you may have been part of this group, please contact Launceston CIB on 6777 3915.

Or information can be provided anonymously by calling Crime Stoppers on 1800 333 000 or online at crimestoppers.com.au