The Tramways Union, which represents workers at the site, said the housing of workers, believed to be Filipinos, at the depot was part of a wider problem where Go Bus was employing foreign workers to keep wages low.
The workers were moved after the Dunedin City Council, which owns the building, informed Go Bus it was illegal under the district plan for people to live in commercial premises "due to fire risk and other safety factors. It would have been unpleasant," council property manager Kevin Taylor said of the suitability of the building as worker accommodation.
The Go Bus worker who made the complaint to the council, which led to the workers being shifted, said he was "fuming" when he found out.
"They had their clothes all ready hanging up in the windows which could be seen from Princes St."
He made the complaint as a "ratepayer" because he did not want the council to be subsidising Go Bus exploiting foreign workers to help keep wages low.
Go Bus South Island operations director Nigel Piper initially said "three perhaps four" migrant workers were housed in the building for less than a week in January last year.
Later, after checking with Dunedin staff, he said there was only one worker housed there.
He said it was only ever a short-term solution while alternative accommodation was sorted out and there was nothing wrong with its actions.
The staff member who made the complaint, who wished to remain anonymous, stood by his accusation there were at least three workers based in the building, saying he witnessed three migrants walking into the building with suitcases.
A Local Government Official Information and Meeting Act response from the council, provided to the Otago Daily Times by the Labour Party, referred to workers as opposed to a single worker.
Mr Taylor said the council acted quickly after receiving the complaint.
"We just asked them to stop and get them out of there, which they did within 24 hours."
Housing the workers in the building was "absolutely" illegal and potentially dangerous.
It puts both the tenant and the landlord at extreme risk if there was any fire in there.
"You haven’t got fire separation between floors, you haven’t got those emergency escape paths."
The building, which was attached to the rest of the depot, was not tenanted by Go Bus, but the company had permission to use it as an overflow building.
The property department received advice on "a couple of points" from the council’s building compliance staff, but it was decided that no further action would be taken because the situation was remedied straight away.
Mr Piper, of Christchurch, said it had arranged other accommodation for the workers, but it was not ready on the day they arrived.
"We had them in there for three maybe four days while the house that we had arranged for them was getting [sorted]."
It was always the plan for them to move out after a short time and it "may well be that the call from the council came at about the time they were moving out".
He would not say it was a mistake to house the workers in the building, saying it was done "to meet a need at the time".
"I guess in hindsight we [should] have contacted the council."
He could not remember whether the company looked for alternative accommodation, such as a motel, but noted Dunedin accommodation was often full in the summer months.
He disputed the claim what it did was "exploitation" and said it treated migrant workers no differently to the way it treated New Zealand workers.
It was "absolute nonsense" that the company brought in migrant workers to keep wages low.
"We brought migrant workers in to fix an issue around driver shortages in Dunedin."
Tramways Union national secretary Kevin O’Sullivan, of Wellington, slammed Go Bus for the way it housed the workers.
The company took advantage of the fact migrant workers were "not keen to rock the boat" and were too afraid to speak up for fear of losing their work visas.
He argued it employed foreign workers to keep wages, which were significantly lower in Dunedin than other centres, down because many New Zealanders were not willing to work for such wages.
