A large blaze at a vitamin supplements factory in Melbourne was deliberately lit, and police are searching for a man spotted fleeing the building with his shoe on fire.

The Boxing Day blaze gutted the building. At least 50 firefighters battled for hours to prevent it spreading to nearby buildings.

Police said a man was seen entering the building just after 4am.

The building's security cameras filmed the man in a dark hoodie and trackpants walking towards the building and carrying a large red petrol container.


A minute later, another camera inside the building shows a burst of smoke and flames.

The man emerges with his left leg engulfed in flames. He stomps his feet as the fire licks at his ankles before running out of the building with his left shoe burning.

A police spokesman said detectives hoped someone may recognise the man from the images, as he probably had burns to his body.