The letters have been reported in 23 counties throughout the state and are part of an apparent attempt to intimidate voters, Department of State spokesman Chris Cate told the Associated Press on Tuesday. The letters were postmarked on Oct. 17 and began showing up in mailboxes on Saturday, according to the Tampa Bay Times. Even the head of the Florida Republican Party got one, according to the Orlando Sentinel.
GOP officials in Florida worked earlier this year to remove noncitizen voters from the rolls, but their initial efforts caught many legal voters. They originally sought to take 2,600 voters off the rolls but that number was later reduced to just 198 names.
Some Republicans suggested that the letters, postmarked in Seattle, were sent in protest of the state's purge effort.
"It would be really disappointing if someone tried to use a successful program to commit voter fraud," Cate said.
The letters appears to originate with Florida's Division of Elections and tell voters they will be removed from the rolls unless they prove their citizenship within 15 days.
The Florida Department of Law Enforcement opened an investigation late Tuesday. Gov. Rick Scott (R) said the state had "zero tolerance" for voter intimidation.
"Anytime anybody's trying to prevent somebody from voting that's a serious issue," Scott said, according to the AP. "We'll get to the bottom of it. We'll turn over any violations of law to law enforcement. I expect law enforcement to prosecute those individuals."