Emergency services are at the scene of a serious crash on State Highway 8, near the Lake Pukaki Visitor Centre.
Police received a report of a car vs campervan crash at around 2:15pm.
Initial reports state that one person is seriously injured.
Three helicopters have been dispatched, two from Christchurch and one from Dunedin.
The Serious Crash Unit has been advised.
The road is blocked.
Motorists are advised to avoid the area.