A General Motors engineer closely associated with the defective ignition switches that led to 13 deaths and millions of recalled small cars seemed "genuinely upset" while being questioned by congressional investigators this week, a House aide told The New York Times.

Raymond DeGiorgio, 61, who was suspended last month with pay in the wake of the ignition switch disaster, spoke publicly for the first time during 10 hours of questioning on May 19.

The engineer has worked at GM since 1991 and was the head design engineer for a range of ignition switches used in various models.

"He came across as if he was just overburdened and just missed it," the staff member, who was not authorized to speak publicly, told the Times.

"He definitely said he was more focused on electrical problems" said the staff member, adding that the man seemed "very emotional at times."

The fatal ignition switches have been connected with 47 crashes, according to GM, which has additionally conducted an internal investigation to see why the issue went unaddressed for so long.

When asked about whether or not he lied under deposition in 2013, DeGiorgio said he had forgotten about signing off to changes to the switch due to the gap of time in between approving the change and being questioned.

The lead design engineer approved a package of changes for the ignition switch in April 2006, according to company documents. After a Georgia woman died in a Chevrolet Cobalt, her family brought a lawsuit against the company; DeGiorgio denied authorizing the switch change in an April 2013 deposition.

DeGiorgio has been suspended with pay along with his supervisor, Gary Altman, since April 10.

In the wake of the 2.6 million-vehicle recall connected with the problematic switches, GM has issued around 30 more recalls for some 15 million recalled vehicles altogether.  

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