In a statement to CNBC, attorneys for Collins vowed to "mount a vigorous defense to clear his good name."
They added: "It is notable that even the government does not allege that Congressman Collins traded a single share of Innate Therapeutics stock. We are confident he will be completely vindicated and exonerated."
Later on Wednesday, Collins issued a statement sharing the "very bad news" with his supporters while vowing to continue his re-election fight for the 2018 midterms in November, according to a New York Times reporter.
Cameron Collins' attorney, Rebecca Ricigliano, said, "We look forward to addressing these charges in court, and will not be commenting on this case outside of the courtroom."
An attorney for Zarsky told CNBC they had no comment at this time.
Collins was Trump's first supporter in Congress, and was reportedly a member of his transition team after the 2016 presidential election. The 27th congressional district in New York, which Collins currently represents, voted for Trump at a higher level than any other district in the state in 2016.
The indictment related to Innate draws new attention to an ex-Trump administration official: former U.S. Health and Human Services Secretary Tom Price, who was grilled by lawmakers during his confirmation hearings in January 2017 about a tip on the company he allegedly received from Collins.
Price resigned last September following an embarrassing series of news stories detailing his use of pricey commercial and charter jet travel during his brief tenure as HHS chief.
HHS' Office of Inspector General last month said the department should try to recoup at least $341,000 that Price had wasted on the flights. Just one out of the 21 such flights he took met all federal requirements, the watchdog said in a report.
A spokesman for Price told CNBC, "Dr. Price addressed his ownership of Innate Immunotherapeutics stock during his confirmation hearings for HHS Secretary and sold any stock he held in February 2017." The spokesman declined to respond to CNBC's questions about whether Price has been contacted by the DOJ in relation to this case, or if he has hired attorneys.
Separately, a source close to Price told CNBC that the former HHS secretary was not questioned by investigators from the Southern District of New York.