The Spencer Street apartment building that caught fire on Monday morning is fitted with combustible cladding. Credit:Simone Fox Koob

The smoke alarm system at a Melbourne CBD apartment block which was ravaged by a blaze this week was "dilapidated" and hadn't been properly maintained, council documents reveal.

An emergency order issued by the council, which was provided to residents on Thursday night and seen by The Age, shows initial inspections by a building surveyor of the Neo 200 tower block has found significant issues with the fire safety system.

This would likely put occupants' lives at risk if they remained living in the units, the surveyor said.

"Following a recent fire in the building, the building's smoke detection and alarm system has been identified as being in a state of dilapidation and it is evident that is has not been maintained in accordance with the requirements of the building regulations such that the safety of building occupants is consequently at risk," the document reads.