Two killed, three critically injured in horror Marlborough crash

A crash on State Highway 1 near Blenheim has left two people dead and three others critically injured.

Emergency services were called to the two-vehicle crash - understood to be between a car and a campervan - at about 10.30am this morning.

In a statement, police said two people died at the scene, despite the best efforts of first responders. 

Hato Hone St John sent four helicopters, three ambulances and two managers to the scene.

It said two people were airlifted to Wellington Hospital in a critical condition, while another was taken taken to Christchurch Hospital, also in a critical condition.

Police said the Serious Crash Unit had been advised.

State Highway 1 has now reopened.

Those travelling between Marlborough and Canterbury were earlier advised to detour via the inland route, with State Highway 1 closed.

The detour could add between two and three hours from Christchurch.