Since early this year, GM has been enveloped in a scandal over why it took more than a decade to begin recalling low-cost Chevrolet Cobalts, Saturn Ions and other cars with the problems that were causing the vehicles to stall during operation.
The sources said U.S. Attorney Preet Bharara's office had asked present and former GM employees to come for interviews.
In addition to Bharara's criminal investigation, Reuters has confirmed that 11 state attorneys general are investigating GM over the ignition-switch problem.
These states are Nevada, Kansas, Iowa, Louisiana, Indiana, Florida, Connecticut, Arkansas, Illinois, Kentucky and New York, sources familiar with the probes told Reuters.
The Detroit automaker recalled 511,528 Chevrolet Camaros on Friday for an ignition switch problem similar to the defect in the Chevrolet Cobalts and other models.
GM has turned over thousands of emails and other documents to help in the probe, the Wall Street Journal reported earlier on Friday.
GM's 3.1 million switch-related recalls are a fraction of the record 16.5 million cars the automaker has recalled this year in 38 actions. That's about as many cars as the entire auto industry expects to sell this year in the United States.
U.S. safety regulators have received at least 18 consumer complaints since 2009 about Camaros involving engines stalling or sudden loss of power, a Reuters review of a National Highway Traffic Safety Administration database showed.
Last week the company dismissed 15 employees, including several high-ranking executives, for their roles in matters relating to the faulty switches in older GM cars.