McDonald's workers sue over 'wage theft'
McDonald's workers in three US states - New York, California and Michigan - have filed cases against the firm alleging it was "stealing" wages.
They allege they were forced to work off the clock and not paid overtime.
Workers in New York said they were not reimbursed the cost of cleaning their uniforms, which they claim pushed their real wages below the minimum limit.
The firm said it was committed to fair treatment of employees and was "reviewing the allegations".
"McDonald's and our independent franchisees are committed to undertaking a comprehensive investigation of the allegations and will take any necessary actions as they apply to our respective organisations," it said in a statement.
The workers have filed a total of seven class action lawsuits in the three states.
In three California suits, workers claim that McDonald's and its franchise owners "failed to pay them for all time worked, failed to pay proper overtime" and "altered pay records".
The cases in Michigan claim the firm "regularly forces workers to show up for work, but then forces them to wait without pay until enough customers show up, and that it also routinely violates minimum wage laws".
Lawyer Michael Rubin, of Altshuler Berzon LLP, who filed the California suits, said: "We've uncovered several unlawful schemes, but they all share a common purpose - to drive labour costs down by stealing wages from McDonald's workers."
The lawsuits come just as President Barack Obama is expected to announce tougher rules on overtime pay.
Fast food companies have already been under increasing pressure to raise wages, and workers at various outlets, including McDonald's, have held strikes in recent months.
Earlier this month, McDonald's said that growing concerns over income inequality may force it to raise its wages.
It said the public focus on the issue "may intensify" over the coming months.