One person is dead and another is seriously injured after a crash involving two vehicles in Canterbury.

The injured person has been taken to Christchurch Hospital by helicopter.

The crash happened shortly before 2.15 this afternoon on State Highway 8 between the Lake Pukaki Visitor Centre and the Mt Cook Road.

The highway is closed, and diversions are in place.

Police are urging the public to avoid the area where possible as delays are likely.

The road is likely to remain closed until at least this evening.

Police say a number of people took photographs of the scene while others tried to help those involved.

They are asking people who took pictures to contact them, to supply copies.

It's the first fatality of the Easter toll period.

Five people were killed on the roads last Easter.