A police officer has suffered minor injuries after a crash on Auckland's Southern Motorway.

The single-vehicle crash happened when the officer was heading to a priority job around 7.30am.

Two lanes of the motorway southbound between East Tamaki Road and Ti Irirangi Drive has been closed, and congestion has been building.

UPDATE 8:40AM

With two lanes still closed the Southern Mwy is congested southbound from Highbrook to Te Irirangi Dr. Consider using alternative route (SH20 or Gt South Rd) to travel south this morning or allow extra time for delays through this area. ^TPhttps://t.co/P7t06pmRnj — NZTA Akld & Nthlnd (@NZTAAkl) January 5, 2020

The Serious Crash Unit is at the scene.