Trays of mail were found along a Wisconsin road on Tuesday, including absentee ballots, local authorities said.
The Outagamie County Sheriff's Office said in a statement sent to The Epoch Times that deputies responded to a reported hazard shortly before 8 a.m. on Sept. 21.
Deputies found three trays of mail on the side of the road and "in the ditch line" off state highway 96.
"The content of the mail was mixed, but did contain several absentee ballots," the sheriff's office said.
The mail was turned over to the U.S. Postal Service.
A postal service spokesperson directed The Epoch Times to the United States Postal Inspection Service, which told news outlets that it began investigating the incident.
President Donald Trump has criticized universal mail-in voting this November, claiming it opens the door to election fraud. He has distinguished between states that automatically send mail ballots to all registered voters and those, like Florida, that only send them to voters who request a mail ballot.
So far, nine states and the District of Columbia plan to hold universal mail-in elections, in which ballots are automatically mailed to all registered voters without the need for voters to first request a ballot. Colorado, Hawaii, Oregon, Utah, and Washington were the only universal vote-by-mail states prior to the pandemic. They have recently been joined by California, Nevada, Vermont, and the District of Columbia. In addition, Montana, North Dakota, and Nebraska let individual counties decide whether to mail ballots to all registered voters.