Some fresh, frozen and canned nonorganic fruits and vegetables are contaminated with concerning levels of pesticides, according to an investigation by Consumer Reports, a nonprofit consumer advocacy organization that provides product reviews and ratings for its subscribers.

Some of the highest levels of pesticides were found in produce imported into the United States, according to the report released Thursday. Sixty-five of 100 samples of the most contaminated produce were imported, with 52 of those samples originating from Mexico.

The majority of the highly contaminated imports were strawberries, typically the frozen variety, the report said. Because they grow low to the ground and are therefore more accessible to bugs, strawberries often top lists of foods contaminated with insecticides.

Imported and domestic green beans also tested high for pesticides, even samples that were labeled organic, “the only organic food we found with significant levels of pesticides,” said James Rogers, director of food safety research and testing at Consumer Reports.