Takata Corp, the Japanese auto parts maker at the center of a massive global vehicle recall, ordered its technicians to get rid of results of tests on some of its air bags after finding cracks in air bag inflators.
The news was first reported by The New York Times.
Tests were carried out on the inflators, steel canisters that contain an explosive used to inflate the bags in the event of a collision, after an accident took place in 2004 when an inflator in a Honda Accord exploded, ejecting metal fragments and injuring the driver.
The newspaper, citing two former Takata employees, said the company retrieved 50 airbags from scrap yards for tests not long after the accident took place.
"All the testing was hush-hush," one former employee said to the newspaper. "Then one day, it was, 'Pack it all up, shut the whole thing down.' It was not standard procedure."
Instead of alerting U.S. federal safety regulators, Takata executives told technicians to destroy all of the test data.
Takata, which has not commented on the report yet, saw its company shares drop as much as 4.7 percent after the news.
At least 11 automakers have recalled more than 14 million vehicles worldwide because of the rupture risks. Four deaths have been tied to the defect, which can cause the airbag's steel canister to crack and explode into pieces when the device deploys during a crash.
"This is a serious allegation about actions taken by Takata," said Honda spokesman Chris Martin in a statement to the newspaper. "It is our intention to determine whether anyone at Honda has any evidence that these claims are credible."
Complaints received by regulators about a number of automakers blame Takata airbags for at least 139 injuries, 37 of which reported airbags ruptured or spewed metal or chemicals.
The unnamed ex-employees said to The New York Times that the test result in 2004 was so upsetting that engineers started designing possible fixes to prepare for a recall. The tests, which were supervised by Takata's then-vice president for engineering Al Bernat, were done in the summer of 2004 at Takata's U.S. headquarters in Michigan, they said.
After three months, an order came in to stop the testing and to destroy the data, which included video and computer backups, the employees told the newspaper.
Tests were conducted four years before Takata said in regulatory filings that it tested the air bags, according to the newspaper.
Takata warned on Thursday of a bigger full-year loss on Thursday and apologized for repeated recalls. The company has 22 percent of the global air bag inflator market.