The Food and Drug Administration is not moving quickly enough to ensure that contaminated food is removed from store shelves, despite being given the necessary authority, federal investigators have concluded.

The inspector general of the Department of Health and Human Services examined 30 of 1,557 food recalls between 2012 and 2015. The investigators found that the F.D.A. did not always evaluate food-borne hazards in a timely manner or ensure that companies initiated recalls promptly, leaving consumers at risk.

Food companies took an average of 57 days to recall items after the F.D.A. was apprised of the potential hazards. One recall did not begin for 303 days, the investigators said.

“Each and every day is important, because every day the product remains on the shelf, consumers are potentially at risk for serious illness or death,’’ said George Nedder, an assistant regional inspector general at Health and Human Services and lead author of the new report.