A female cyclist has been flown to Middlemore Hospital in a critical condition following a collision with a truck near Auckland Airport.
A police spokeswoman told the Herald the collision occurred about 4.30pm. Motorist are being warned to expect significant delays and find alternative routes to the airport.
Images from the scene show a bike which has been moved to the kerb.
Auckland Westpac Rescue Helicopter spokesman Lincoln Davies said the helicopter was called because it was peak traffic time.
"[The cyclist] suffered a severe leg injury and needed to be given blood by our onboard HEMS (Helicopter Emergency Medical Service) doctor," he said.
The truck involved is parked behind the intersection of Verissimo Dr and George Bolt Memorial Dr and emergency services are standing nearby.
Fire and Emergency New Zealand staff could earlier be seen holding a grey tarpaulin in front of the collision scene, preventing passersby from viewing the scene.
NZTA said earlier that the crash on SH20A affected traffic to Auckland Airport.
"The NZ Transport Agency advises motorists that a crash on SH20A to Auckland Airport is causing delays.
"The crash is at the intersection with Verissimo Drive. Two lanes are blocked, but one is open. The Police Serious Crash Unit has been advised."
Traffic on SH20 and 20A was heavy and backing up.
Motorists were advised to try using SH20B to reach the airport, but traffic on that route was also heavy and delays likely.