Auckland Southwestern Motorway lanes reopen after rock spill near Onehunga

Rocks were reported strewn across multiple lanes on Auckland's Southwestern Motorway. Photo / NZTA

A spill of rocks closed lanes on a busy Auckland motorway for two hours tonight.

The spill happened on the southbound lanes of the Southwestern Motorway near Onehunga and caused major delays.

Police said the incident near the Neilson St offramp happened about 6.20pm.

NZ Transport Agency Waka Kotahi said at 8.30pm all lanes had reopened after crews worked to clear the road.

An image released by NZTA showed traffic had backed up the hill towards Hillsborough.