Federal investigators have identified hundreds of people suspected of illegally obtaining loans designed to help businesses struggling amid the coronavirus pandemic, U.S. Justice Department officials said Thursday, while pledging to aggressively prosecute fraud against the government relief program.

“The amount of fraud that we’ve uncovered to date and that we’ve prosecuted to date is significant. The amount of fraud that we’re currently investigating and anticipate charging in the future is also significant,” Brian Rabbitt, the acting head of the Justice Department’s criminal division, said. “And, given what we’ve seen so far, we believe there’s an additional set of fraudulent activity out there that we intend to continue pursuing.”