Rhythm and Alps has announced two artists will not be playing at the Wanaka festival due to the Covid-19 pandemic.
DJs Friction and another act DJ Dimension are no longer in the line-up.
Festival organisers said it was due to the impact of Covid-19.
DJ Dimension subsequently confirmed on social media that he was New Zealand's first Omicron case in the community.
The sold-out Wanaka music festival started today and will be one of New Zealand's biggest destinations for New Year celebrations.
There were also other losses to the line-up as a result of problems caused by the pandemic.
Sampa the Great was not able to leave South Africa as all flights were cancelled, and Harriet Jaxxon, Lenzman, CC:Disco!, and Bradley Zero were not able to get MIQ rooms to enter New Zealand.
Festival director Alex Turnbull said Rhythm and Alps sold out yesterday morning.
He told RNZ on Wednesday night that organiser were waiting for information to come through from the Ministry of Health on the status of the DJs.
"We don't really know much but what we do know is that for the safety of all our customers and whānau at Rhythm and Alps, they won't be attending Rhythm and Alps or heading to the South Island."
Turnbull said people were encouraged to upload their Covid-19 vaccine passes before arriving, and staff would follow procedures closely.
"So you know, it'd be pretty hard to be fraudulent, and if someone doesn't have their conditions of entry sorted, that's the way it's gotta be."
Sister festival Rhythm and Vines and popular festival Northern Bass have been postponed until 2022 because of Covid-19.