Some $2.3 million was stolen from the Wisconsin Republican Party's account by hackers, according to the party's chairman.
Hitt said the FBI is investigating the hack.
He said the hack may have been through a phishing attempt, which is the fraudulent practice of sending emails purporting to be from reputable companies in order to get individuals to reveal passwords and other personal information.
“There's no doubt RPW [the Wisconsin GOP] is now at a disadvantage with that money being gone,” Hitt told the news agency, adding that the party and Trump's campaign needs the cash to make decisions quickly with just days to go before the Nov. 3 election.
Hitt said the Wisconsin GOP had contracted four vendors to send direct mail and provide pro-Trump hats and other materials to supporters. When the Wisconsin GOP paid for those services, the funds went to the hackers rather than the vendors, he told the AP.
The Wisconsin Republican Party didn't respond to a request for comment.
Trump won the state by fewer than 30,000 votes in 2016 over Hillary Clinton, and the president has frequently visited the state during the 2020 election cycle.
Joe Biden, Trump's Democratic presidential rival, is also slated to visit Wisconsin on Oct. 30, although the location and timing are unclear, according to the paper.
The message also linked to two Monero cryptocurrency addresses.