Workers brought to Canada by a B.C. contractor to work at the Canada Royal Milk plant in Kingston, Ont. lived in overcrowded conditions that violated local fire and building codes until the city's fire inspectors intervened.

But now, some of their former co-workers at the plant say work they were doing there was also unsafe, even though CBC News has learned the contractor was issued work permits reserved for those offering expertise "of significant economic benefit to Canada."

Current and former employees of the baby formula manufacturer told CBC News that the company was very hierarchical in its early months of operations and that these contracted workers from China were treated like "second-class citizens" at the bottom of its organizational structure. CBC is protecting their identities because they fear a backlash for speaking out.

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