Election board officials in Illinois said that more than 500 noncitizens were able to register to vote, and at least 19 of them did so in the 2018 election.

“The State Board of Elections says out of the 547 non-citizens, 19 of them voted in 2018. Working now to confirm their exact location. Macon County Sheriff's race was decided by just one vote in 2018. 7 of the 547 non-citizens were registered in Macon County,” Mark Maxwell, a reporter for WCIA, tweeted Tuesday.

Update: the State Board of Elections says out of the 547 non-citizens, 19 of them voted in 2018. Working now to confirm their exact location. Macon County Sheriff's race was decided by just one vote in 2018. 7 of the 547 non-citizens were registered in Macon County. https://t.co/pmJd3N5kSZ — Mark Maxwell (@MarkMaxwellTV) January 21, 2020

Illinois Secretary of State Jesse White’s office admitted fault for the incident but referred to it as “isolated” and insisted that the “error” had been fixed, according to WCIA.

State Republicans are seeking more information about the controversy, and five GOP lawmakers have sent a letter to the Democratic House speaker to express their outrage.

“This is an absurd lack of compliance with state law, surfacing less than three weeks from the opening of early voting for our state’s 2020 general primary election,” the GOP lawmakers wrote.

“Given this, we are requesting an immediate hearing of the House Executive Committee to investigate this situation and to hear testimony directly from Secretary of State Jesse White, officials of the State Board of Elections, representatives from our local election authorities, and others concerned with this situation.”

Illinois residents are permitted to receive driver's licenses and photo IDs regardless of their immigration status.