Emergency services are responding to a crash on SH6 north of Nelson.
The crash, involving a motorbike, occurred about 4kms north of Kokorua Rd shortly before 6.30pm.
A police spokesperson says the road is currently blocked in both directions and asks that motorists avoid the area.
It is expected to be closed for approximately one hour.
A man was airlifted to Nelson Hospital in a serious to critical condition.
