Second fire at Melbourne caravan factory

A suspicious fire has badly damaged a caravan factory in Melbourne two days after several vehicles were set on fire at the same site.

The interior of the Merola Way Campbellfield business was completely alight when emergency services arrived at about 3.30am Wednesday, police said.

It took an hour to bring the blaze under control, but there are concerns the building may collapse.

Nobody has been injured, police said.

Firefighters had already been called to the factory site on Monday morning after two cars and a caravan were set on fire in the forecourt and the office was broken into.

Police are investigating whether the two incidents are linked.