Auto industry experts and lawmakers have slammed automaker Volkswagen for allegedly breaking the public's trust during a congressional hearing on Thursday, Oct. 8.

Michael Horn, the chief executive of the company's American division, apologized for the emission scandal on behalf of the whole company before the House Energy and Commerce Committee.

However, he did blame a few software engineers for secretly devising the cheating scheme.

“This was a couple of software engineers who put this in for whatever reason,” Horn said during the subcommittee hearing. “To my understanding, this was not a corporate decision. This was something individuals did.”

Horn disclosed that three engineers were already suspended for loading "defeat devices" in the company's diesel vehicles, which resulted to lower emissions throughout the testing. He also claimed he only learned about the issue only a few days before Volkswagen came clean to the Environmental Protection Agency (EPA).

The executive likewise admitted it would take several years to repair all of the nearly 500,000 cars affected in the United States.

Experts' Reactions

Rep. Morgan Griffith, R-Va., said he's very disappointed in Volkswagen, saying he owns a Volkswagen diesel car – a 2012 VW Passat – which is among the affected vehicles.

A few lawmakers also doubted the cheating scheme was devised by the company's engineers.

“I cannot accept VW’s portrayal of this as something by a couple of rogue software engineers,” said Rep. Chris Collins, R-N.Y. “Suspending three folks — it goes way, way higher than that.”

Meanwhile, the former administrator of the National Highway Traffic Safety Administration, Joan Claybrook, believes the engineers did not act unilaterally. She went on to say the company boasts teams in putting the cars together and that they do have a review procedure for the development, designing as well as testing of the automobiles.

Lawmakers also blasted an EPA official, Christopher Grundler, who testified after Horn.

Rep. Michael Burgess, R-Texas, questioned the EPA's yearly budget size, saying a West Virginia University study which only had a budget of less than $70,000 had managed to discover the cheating scheme.

"With all due respect, just looking at the situation, I think the American people ought to ask that we fire you and hire West Virginia University to do our work," Burgess said.

In September, EPA announced it would toughen its emissions testing in response to the Volkswagen emission scandal.