Update: SH1 reopens

SH1 near Redwood Pass, site of a fatal crash on Sunday morning, has reopened following about a six-hour closure, NZ Police announced in a 5:30pm update.

"Temporary speed limits are in place, and Police thank motorists for their patience," the announcement noted.

Emergency services first responded to the two-vehicle crash around 10:40am. The initial announcement from police indicated "serious injuries" but did not specify the number or severity.

In an update at 2pm, police said: "Despite best efforts by emergency services, two people died at the scene."

As the Serious Crash Unit continued investigating the crash, police advised that SH1 "will be closed for some time" and motorists should "expect delays or avoid travel to the area."