U.S. inspectors who toured the Johnson & Johnson plant at the center of last week's recall of widely used liquid children's products uncovered unsanitary conditions in at least one lab, according to a government report released on Tuesday.

The U.S. Food and Drug Administration (FDA) said in the report, dated April 30, that its inspectors found thick dust and grime covering certain equipment, a hole in the ceiling and duct tape-covered pipes at the Fort Washington, Penn., facility where 40 products recalled last Friday were made. Inspectors also found a lack of quality control procedures and poor handling of complaints, according to the report.

On Saturday, the FDA urged consumers to stop using liquid Tylenol, Motrin, Benadryl and Zyrtec for children and infants after a broad recall by Johnson & Johnson's consumer division late on Friday. Read the full list of more than 40 affected products made by McNeil Consumer Healthcare here.

McNeil said it was recalling the products in consultation with the FDA after discovering manufacturing deficiencies that could affect the quality, purity or potency of the medicines. On Tuesday, the FDA posted the inspection notice.