At the Justice Department's press conference Wednesday in Washington, D.C., FBI Deputy Director Andrew McCabe said it was "now clear that Volkswagen top executives knew about this illegal activity and kept their shareholders and the public in the dark."
He said the government's settlement with VW and the resulting indictments are "a great example of the fact that no corporation is too big, no corporation is too global, and no person is above the law."
McQuade said the U.S. investigators have "worked closely and collaboratively with German prosecutors" as they developed their cases. "They’ve provided some evidence to us, and they know about ours," she said.
'Not some chump'
She also said that as the investigation widened, "some VW employees have been cooperative in providing information to us." She said she didn't have any information about potential extraditions from Germany but said that Justice officials "will explore our options for getting them here."
McQuade said other automakers need to closely watch the VW case unfold, not just as a warning against wrongdoing but also as a message that such wrongdoing will eventually carry consequences.
"If you are an automaker that plays by the rules, you are not some chump who is going to be competitively disadvantaged because you chose to act within the law."
Christiaan Hetzner and Reuters contributed to this report.