The Spencer Street apartment building that caught fire on Monday morning is fitted with combustible cladding. Credit:Simone Fox Koob Assistant Chief Fire Officer Trent Curtin said firefighters were hindered in their efforts to battle the blaze and evacuate residents due to overcrowding inside the complex. "When firefighters go into a small apartment building, there’s an expectation of the number of people who live in that apartment," he said. "In some cases in some apartments we observed up to 10 beds in an apartment. This makes it more difficult for firefighters when they expect small numbers to find large numbers of people requiring evacuation."

Following the fire, Melbourne City Council's building surveyor issued an emergency order that said the building could not be occupied for 48 hours, but this was extended on Tuesday afternoon. Authorities have given no firm indication on when residents will be able to return home. However, a message sent to residents from the owners' corporation general manager Ablo Jalloh on Tuesday told residents seek to alternative accommodation for at least the next two nights and they will be reimbursed. Japanese international students Mitu Ota, 21, Chihiro Nakayama, 31 and Seira Miyabe, 26, were sleeping inside an apartment on the 25th floor when the fire broke out. They've been told their apartment was severely damaged in the blaze and they have been given no indication of when they will be able to return home.

"It's been really hard because we don't even know how much our things were damaged," Ms Miyabe said. "Some of us had our laptops and cameras were the floor so we are worried about our belongings, but also about our studies as we have assignments due." The three students are staying at a hotel across the road from the apartment complex. Japanese international students Mitu Ota, 21, Chihiro Nakayama, 31 and Seira Miyabe, 26, were sleeping inside an apartment on the 25th floor when the fire broke out. International student Khulood Al Hamhami said she woke to the sound of a fire alarm blaring in the early hours of Monday morning. "I went out onto the balcony and I could see black smoke everywhere and it just filled the apartment," the 23-year-old from Oman said.

Ms Al Hamhami, who studies at Swinburne University, said she and three other international students who also live in the tower had been sleeping on the floor in the loungeroom of their friend's apartment nearby. "I have lived in this apartment for four years and there have been so many fire evacuations in that time," Ms Hamhami said. Investigators believe the fire's likely cause was a discarded cigarette that ignited combustible materials stored on the balcony. The council confirmed on Tuesday it was also investigating issues of overcrowding in the apartment building after an inspection discovered that some apartments had more beds than deemed appropriate. Residents outside the apartment tower on Monday morning. Credit:Jason South

A council inspection found the fire affected "essential safety measures" of the building, including the sprinkler system and fire alarms. Some residents were allowed to return to the building briefly to collect vital possessions on Monday night and they had brief access again on Tuesday, the council said in a statement. Investigators say several apartments of the floors ravaged by the fire have been significantly affected by fire and water damage. There has also been extensive damage to the floors above and below. An emergency relief centre has been reopened at the Melbourne Town Hall to support those affected.

Residents told The Age on Monday that balconies were often crowded with possessions and the problem was hard to police. "It's private property, you can't just go into private property," one resident said. "The council can check for overcrowding but they have to give warning ... We know we have had beds in the stairwell [in the past]." The tower has a history of fires and overcrowding.

A fire broke out at the apartment block as recently as last year. Neo200 was also hit by fire on New Year's Eve 2015 shortly after it emerged it had harboured illegal rooming houses, with living rooms rented to tenants as sleeping spaces. Residents were told a towel or some kind of rubbish had been left on a balcony air-conditioning unit, sparking the blaze. Almost 30 firefighters fought the blaze on the 29th floor in 2015. It did not spread to other levels, but the the 29th floor was left with extensive water damage.

The Neo200 apartment complex has cladding material on its balconies similar to that used on London's Grenfell Tower, where 72 people died in a fire in 2017. But it was deemed safe to occupy after an audit prompted by the Lacrosse tower fire in Docklands in 2014. LU Simon, the builder of the Spencer Street tower, also built the Lacrosse building. The Neo200 tower was rated a "moderate risk" in a statewide audit of buildings with combustible cladding that followed the Lacrosse fire. The moderate rating means the tower is not a high priority for replacement work.

When asked what the builder knew about the cladding and if any steps had been taken to remove it, a spokeswoman for LU Simon said "we are not in a position to comment as we have not received sufficient information or any official reports". No serious injuries were reported but a man in his 20s was treated for smoke inhalation and taken to hospital in a stable condition.