The Fire Service has left the site of a massive fire in an industrial area of Auckland.

The blaze at the Southdown Freezing Works in Penrose started on Friday night and was fully extinguished at around 2pm.

The fire covered an area of three football fields and at its height took 30 fire appliances 120 crew to tackle.

A previous fire at the site in December 2008 burned for 15 days.

Developer John Sax believes the fire was the work of an arsonist because an accelerant was apparently used and the complex was under constant security.