EXCLUSIVE

A Docklands apartment tower gutted by fire last month was being used by some residents as slum housing for suspected illegal workers and foreign students.

The discovery has led to an investigation by Department of Immigration and City of Melbourne. The two bodies were called in after fire fighters and safety inspectors found up to eight mattresses were crammed into some two-bedroom apartments in the Latrobe Street building.

The packed conditions in the units likely created a potentially "very dangerous situation" for all residents in the tower.

"When there's overcrowding it effects the safety of an entire building," said Metropolitan Fire Brigade Commander Darren Conlin, of the building inspection and compliance division. "During an evacuation there will be more people trying to get out than the building was designed for."