Substandard cladding has been blamed for the rapid spread of a fire that caused more than $2 million worth of damage to a high-rise apartment building in Melbourne's Docklands in November.

It took more than 80 firefighters about 30 minutes to bring the blaze under control, which burnt from the Lacrosse Docklands tower's sixth floor to the top of the building on the 21st floor.

The Metropolitan Fire Brigade (MFB) found that the blaze, which caused the evacuation of 500 people, was accidentally sparked by a cigarette butt on a balcony.

The MFB said the building's external cladding did not meet building code requirements, and allowed the blaze to spread quickly up the building.

Peter Rau, chief officer at the MFB, said if the cladding had have been up to building code standard, the fire would not have spread as quickly.

"The fire spread would have been vastly different in my view ... the fire went to the 21st storey," Mr Raus said.

"The view of the investigation team is that it would have continued to the height of whatever the building was so I've got great concerns with the products that were in place there."

The Victorian Building Authority (VBA) has been asked to investigate the quality of cladding being used in construction and whether stricter regulations are required.

The VBA's Jarrod Edwards said the authority would look into the conduct of the builder and building surveyor, as well as investigating whether the same material had been used in other buildings.

"The VBA has begun contacting all relevant building practitioners and will work with them to determine if non-compliant building material has been used incorrectly during the construction of other buildings in Victoria," Mr Edwards said.

The MFB also found that firefighters found "high occupancy rates" in some apartments and excessive amount of combustible storage on balconies.

"In this particular situation the factors that caused this fire to be such an extent were numerous - the discarded cigarette, the poor house-keeping and the external cladding which didn't prevent the fire from going any further," he said.

Mr Rau said 12 recommendations had been made by the report following the investigation.

"There are a number of things in the report that we're interested in trying to pursue, and we certainly will with the relevant authorities and agencies," he said.

The MFB said the sprinkler system and evacuation worked well during the fire.

Class action considered on fire

Law firm Slater and Gordon said 100 owners and residents of the building had registered their interest in launching a class action over the blaze.

Litigation lawyer at the firm Ben Hardwick told 774 ABC Melbourne that owners were asking how the building was approved for occupancy, considering the combustibility of the external cladding.

"This is an epic failure of our building surveying system," he said.

"The occupancy permit for this building was only issued in 2012, so this is not like some building product that was built 20 years ago, this is in very recent times.

"So our clients, owners and residents are really having salt rubbed into the wound.

"Not only did they have a fire in their apartment building, which was distressing and very costly and many residents have only just reoccupied the premises now - but now they find out that the whole of the external cladding of the building ... needs to be removed and re-instated, which is going to be, one would expect, a hugely expensive exercise."

He said Slater and Gordon was investigating the potential for class action to recover losses from the fire.

"The critical question for our clients is - who's going to pay for all this?" he said.

"The obligations in relation to the choice of materials, will rest with a number of building practitioners, including the builder and the building surveyor and these are the questions will be seeking answers to."