WASHINGTON (AP) - A top Food and Drug Administration official will tell Congress Thursday the agency should have acted sooner to halt a secret recall by Johnson & Johnson last year, in which the company quietly purchased defective painkillers from stores.

FDA deputy commissioner Joshua Sharfstein plans to disclose new details about when the agency learned of the so-called phantom recall, according to prepared testimony obtained by The Associated Press.

Sharfstein states that J&J informed the FDA of its purchasing plan in April 2009. Previous FDA statements suggested the agency learned of the plan in July, when it demanded the company conduct a formal recall.

The recall is part of broader congressional investigation into quality problems that have forced J&J to recall millions of bottles of painkillers in the past year, with problems ranging from contamination with bacteria to tiny metal shards.

The chief executive of J&J also is set to tell Congress his company "let the public down" with a string of quality problems.

William Weldon is scheduled to testify Thursday morning before a House panel investigating the company's unprecedented succession of recalls. The maker of trusted brands like Tylenol, J&J has announced nine product recalls since last September,

In prepared testimony, Weldon also suggests the company made a serious mistake last year when it hired contractors to buy up bottles of defective lots of Motrin, rather than issuing a formal recall. The pills in question did not dissolve correctly.