An Australian woman has claimed she is being used as a 'guinea pig' after she was arrested for allegedly voting in two US elections despite being a lawful American resident for nearly 30 years.

Denise Nataly Migliore, 51, who lives in Louisiana, was charged on June 11 with four counts of illegal voting in an election and making false statements to register to vote.

The US Attorney's Office for the Eastern District of Louisiana levelled the charges against Ms Migliore following an investigation by Immigration and Customs Enforcement (ICE) and the Federal Bureau of Investigation (FBI).

It alleged Ms Migliore, who was born in Sydney, made false claims about being a US citizen to register to vote in October 2022 and October 2024.

She's then accused of illegally voting on November 8, 2022 and November 5, 2024.

When Americans register to vote online they are required to tick a box asking if they are a citizen.

Ms Migliore told local media outlet NOLA she thought she had a right to vote.

'I have been here almost three decades, I had a pending application for citizenship, and I just considered myself a citizen,' she said. 'I just didn't realise that it was such a big deal.'

She claimed she was interviewed twice by US federal agents, but only found out about the charges through the media, before she was later arrested at a federal courthouse in New Orleans on July 1.

Ms Migliore also claimed that when she turned up to allegedly vote at a polling booth in 2024, she showed her ID and wasn't asked if she was a citizen.

'I feel like I'm being used as a guinea pig to show how flawed the electoral system is and I'm being unfairly targeted,' she said.

The US has experienced controversial widespread crackdowns on immigration rules under Donald Trump's presidency, resulting in mass protests and well-publicised clashes between the public and Immigration and Customs Enforcement (ICE) agents.

Trump on Tuesday addressed Ms Migliore's arrest on his social media platform, Truth Social.

'Australian alien arrested after investigation finds she illegally voted in two federal elections,' he wrote. 

Homeland Security Acting Assistant Secretary Lauren Bis said: 'Her arrest and charges are the result of the hard work of the men and women of ICE law enforcement and our federal partners.

'Our message to aliens who vote in American elections is clear: we will find you, arrest you, and you will face the consequences, including criminal charges and deportation.

'Only Americans should be electing American leaders.'

Trump has previously claimed immigrants have illegally swayed the results of federal elections, a theory which has been debunked through analysis of voting data. 

That data found cases of illegal voting by immigrants were extremely rare.

Ms Migliore was living in Franklinton, Louisiana, at the time of her arrest.

If convicted, she faces a maximum of five years behind bars and three years of supervised release, as well as fines up to US$250,000.

The Australian Department of Foreign Affairs and Trade confirmed it is providing consular assistance to an Australian in America.