According to the newly-unsealed indictment, timely sales based on inside information allowed Cameron Collins, Zarsky and others to avoid losses totaling more than $768,000 when the biotech company, Innate Immunotherapeutics Limited, failed a key clinical trial in June of a year ago.
Cameron Collins is accused of passing on that information to his fiancee's father, Stephen Zarsky, and others, who also benefited financially from the insider knowledge.
In total, the three defendants avoided "over $768,000 in losses that they would have otherwise incurred" had they sold their stock after the information was made public, according to the indictment.
Collins, who represents Buffalo's suburbs and counties in upstate NY, was the first House Republican to openly support Trump's bid for the party's nomination in the 2016 race, and he has remained a loyalist to the president.
OH 12th Congressional District Special Election Results
The Republican campaign arm and its allied super PAC was forced to pick up the slack, spending more than $4 million between them. Danny O'Connor, a Democrat from Ohio and US Representative candidate, in Columbus, Ohio, before the vote.
Berman's office will hold a press conference at noon. Price and Collins purchased almost $1 million in discounted stock in the company.
"At the time Christopher Collins, the defendant, received this email, he was attending the Congressional Picnic at the White House", the indictment says.
Lawyers for Collins said the congressman would be "completely vindicated".
They added: "It is notable that even the government does not allege that Congressman Collins traded a single share of Innate Therapeutics stock".
No allegations of misconduct have been leveled against him or Conaway, a former chairman of the House Ethics Committee.