WASHINGTON -- Congressional investigators said Thursday that Johnson & Johnson hired a private company that bought up defective packets of pain relievers in 2008 before recalling the pills months later, after prodding from federal regulators.

The new questions about J&J's handling of quality issues came in a hearing about its latest recall involving more than 100 million bottles of children's medicine.

"This is an issue of trust, when parents and grandparents give these medicines to their children they want to be confident that they are not harmful," said Rep. Edolphus Towns, D-N.Y., chair of the House Committee on Oversight and Government Reform.

Last month J&J's McNeil division recalled more than 40 varieties of children's medicines after the Food and Drug Administration discovered violations at a company plant. The FDA has not linked the recalled products to any health problems.

Colleen Goggins, J&J's president for McNeil consumer products, said the company has taken steps to fix the problems. But she had few answers to questions about an alleged "phantom recall" of more than 88,000 packets of Motrin, a pain reliever.

According to FDA documents, J&J learned about a formulation problem in November 2008 that interfered with the pills' dissolving action, causing them to lose potency. J&J then hired an outside contractor to collect samples of the product and determine if a recall was necessary.

But the contractor began purchasing large quantities of Motrin and instructing its employees not to mention a recall.

A memo titled "Motrin Purchase Project," distributed during the hearing states: "You should simply 'act' like a regular customer while making these purchases. There must be no mention of this being a recall of the product!"