Emergency services at the scene of the crash. Photo: Toni MsDonald

One person has died following a serious two-vehicle crash involving a truck on State Highway 1 near Bluff this morning.

The crash, in the Greenhills area near the intersection with Stanley Township Rd, was reported around 6:10am, police said.

The road was blocked in both directions until about 4pm. 

The Serious Crash Unit was investigating, police said.

Waka Kotahi NZ Transport Agency said it was a serious crash and all emergency services were attending.

A witness said the truck was a chip liner and trailer, and the trailer was on its side.

The car was "unrecognisable" under the front of the truck, they said.

Yesterday, a truck rolled on the same stretch of highway, closing the road for about two hours.

The driver in that crash was not injured. 

MetService has a strong wind watch in place for coastal parts of Southland, Clutha and Dunedin, and urges motorists in lighter or high-sided vehicles to take extra care.