Mexico did not say what violations were found at the plant in the northern border state of Sonora, and said testing was being done to find the source of the contamination.
Inspectors took samples of water and swiped surfaces at the plant to look for traces of salmonella bacteria.
Since October, at least 230 people in the U.S. and 129 in Canada have been sickened in this outbreak.
The cantaloupes implicated in this outbreak include two brands, Malichita and Rudy, that are grown in the Sonora area.
The fruit was imported by Sofia Produce LLC, of Nogales, Arizona, which does business as TruFresh, and Pacific Trellis Fruit LLC, of Los Angeles. So far, more than 36,000 boxes or cases of cantaloupe have been recalled.
Health officials are warning consumers, retailers and restaurants not to buy, eat or serve cantaloupe if they don’t know the source.