The NZ Transport Agency says the Southern Motorway at Takanini is due to be closed to all northbound traffic shortly due to a fatal crash.
The incident happened just before the Walter Strevens Bridge around 7.30am this morning.
Police have requested all northbound motorway lanes are closed while they investigate.
Traffic is already heavy in the area, with congestion back to Drury.
Motorists are advised to delay their travel or take alternative routes via Great South Road at Papakura.