The Manitoba Employment Standards Branch is investigating Emterra, the company hired to pick up Winnipeggers' garbage and recycling.
The province confirmed to CBC News that an investigation is underway, but officials would not say what it's about or who filed the complaint that would have initiated the probe.
Emterra holds the City of Winnipeg contract to pick up garbage, recycling and yard waste as part of a revamped citywide collection system that launched on Oct. 1.
But the company fell behind schedule soon after the new system began, resulting in many residents complaining that their garbage pickup had been delayed by days.
The city has imposed deadlines and threatened Emterra with penalties if the pickup service is not caught up.
Mike Davidson of CUPE Local 500, the largest union representing City of Winnipeg employees, told CBC News that he worries that Emterra staff are being overworked to meet deadlines.
Long hours can be dangerous for workers, said Davidson, who is callling for an independent audit of the city's waste collection system.
St. Vital Coun. Brian Mayes said one former Emterra employee has told him there are issues with overtime.
Earlier this week, city officials said the company has made improvements over the last week, but collection services still aren't at the level required under its contract.
The city is urging residents to call 311 if their garbage and recycling pickup does not take place as scheduled.
Emterra's contract began Aug. 1 in a part of the city that used to have large shared community garbage bins, also known as autobins, according to city officials.
The new garbage collection system fully launched on Oct. 1, affecting about 165,000 residents in the rest of the city.