A police car has been badly damaged in a three-car crash in Otahuhu this morning.

A witness, who did not want to be named, said the patrol car whizzed past him on Great South Rd by Fairburn St and banged into the other vehicles.

"I just walked past it," the witness said.

"I heard a siren zooming past me and bang when it got around the corner...three cars damaged a silver ute."

Advertisement

A police spokeswoman said the crash happened around 11.50am.

"The police car was on the way to an event at the time. The police car has then hit the back of a second car."

The driver of the other vehicle sustained whiplash injuries and was taken to Middlemore Hospital as a precautionary measure.