Alarmed by a report a decade ago that one of its airbags had ruptured and spewed metal debris at a driver in Alabama, the Japanese manufacturer Takata secretly conducted tests on 50 airbags it retrieved from scrapyards, according to two former employees involved in the tests, one of whom was a senior member of its testing lab.

The steel inflaters in two of the airbags cracked during the tests, a condition that can lead to rupture, the former employees said. The result was so startling that engineers began designing possible fixes in preparation for a recall, the former employees said.

But instead of alerting federal safety regulators to the possible danger, Takata executives discounted the results and ordered the lab technicians to delete the testing data from their computers and dispose of the airbag inflaters in the trash, they said.

The secret tests, which have not been previously disclosed, were performed after normal work hours and on weekends and holidays during summer 2004 at Takata’s American headquarters in Auburn Hills, Mich., the former employees said.