Police are investigating a major break-in at a South Auckland car rental yard -- where almost 100 vehicles were stolen on Friday night

It's understood the Jucy Rentals vehicles were stolen from the company's Mangere yard.

The exact number is yet to be confirmed until a full stocktake of all Jucy yards is completed.

The stolen cars were Holden Captivas, Mazda 3s or Suzuki Swifts and were plain without branding, making them not easily identifiable as a Jucy rental vehicle

So far, close to 20 vehicles have been found in Otara, Mangere and Papatoetoe -- but dozens are still missing.

Police increased patrols in the area over the weekend.

Multiple arrests have been made in relation to the heist.