Richard Hopkins’s claim that a postmaster in Erie, Pa., instructed postal workers to backdate ballots mailed after Election Day was cited by Sen. Lindsey O. Graham (R-S.C.) in a letter to the Justice Department calling for a federal investigation. Attorney General William P. Barr subsequently authorized federal prosecutors to open probes into credible allegations of voting irregularities and fraud, a reversal of long-standing Justice Department policy.

But on Monday, Hopkins, 32, told investigators from the U.S. Postal Service’s Office of Inspector General that the allegations were not true, and he signed an affidavit recanting his claims, according to officials who spoke on the condition of anonymity to describe an ongoing investigation. Democrats on the House Oversight Committee tweeted late Tuesday that the “whistleblower completely RECANTED.”